dog adopted being retained

Question
We truly need some help to try to get our dog back.
We adopted a "Daschund/Shepherd Mix" from a rescue group on 8/13 at PetSmart. She's said to be 4-mo-old.  We had her for 4 full weeks.  She is actually a very lovely dog in many ways, and appears to be very intelligent, but also very active, not yet house-broken, and she is very strong and somewhat aggressive and quite territorial and dominating towards our 8-year-old.  We have a 8-year-old Shih-tzu-Poodle male since he was 9 weeks old.  Our 8-year-old is very mild and is a very friendly dog.  We took care of the newly adopted new comer for 4 full weeks, and I was spending like 8-10 hours and more a day with her every day and the other dog, trying to clean up, play with them, to go outdoor, self-training, ... etc.  The time was very demanding, and worries also grew if she might ever be able to adjust and co-exist well with our 8-year-old at all.  We spoke with the Rescue group and was told it would be unfair to not to allow the 4-mo-old playmate, and it would also be unfair to take away what our older dog already has had in the house for so long, and we were encouraged to return the 4-mo-old and get another older dog.  I had sent the 4-mo-old to PetSmart for a 1/2 hour training session to show her to "sit" and "leave it", but at the time, we really could not afford any more training costs -- even though we truly felt that professional training would have been our last resort before we had to send her back to the Rescue group.  I was thinking maybe someone else would be more capable than us and could provide a better home and a fuller life for this very active and strong girl-dog than we could provide.  My husband and I are both into our early 50's, self-employed, we are not active people, but we truly love our pets in our house and we believe we take excellent care of the pets.  We returned the adopted dog on 9/10 but immediately wanted her back the same night, but since then we have had encountered terrible responses from the Rescue Group, such as they said they did not want me to touch their dogs at all, that we were terrible dog owners, and they hung up the phone when I tried to call and pleaded for my dog's return.  I have sent them numerous e-mail and offered many other long-term support donations to get my dog back as well, but there is no response.  I am still donating online indicating payment for monthly heartworm and flea/tick treatment for my dog and her brother from the same litter to this Rescue group.     

We missed the 4-mo-old (now 5-mo-old) badly and I think of her every day and nights. I have a lot of digital pictures of her on my computer.   It was a very hard and sad decision to make to return her, but that had a lot to do with the advice from the "Rescue" group.  It put us in tears for 2 weeks just thinking about returning her before we returned her, and more tears and tears and guilt after we had returned her on 9/10.  Each dog is different, and this one is one special dog to me.  
Two days after we returned the "Daschund/Shepherd", we went to a city shelter and my husband literally fell in love with a "Poodle Mix", and we were successful in taking him home after two days.  He's about 1 year old, house-broken and seems well-trainined in certain activities and movements.

The Rescue group is now telling people that they have to either take BOTH dogs (our girl-dog and her brother) together, or unless people already have one dog about a year old in the HOUSE (not apartment), and they have to know exactly what dog, etc., before they would let anyone adopt the "girl-dog" that I have returned.  They said they wanted to have 6-7 applications before they decide.  The Rescue group is not responding to my e-mail or donation at all.
We are still trying to get my dog back and trying to assess what legal position we may be in at this point. Are we losing all our right to the guardianship of the dog just because we gave her back to the Rescue group for a day?

Answer
Katherine,

Oh boy.

What I know about rescue is that it is a very stressful undertaking from the organizational standpoint.  While it sounds like you did work hard for this dog, you still gave it back.  Giving back a dog means the rescue failed to get the permanent home and they take it personally.  All rescues are almost always over capacity with unwanted dogs.  Any additional dog is a burden that they feel obliged to help as their cause.

Does that help you understand their position better?

It also sounds like you fall in love too easily with any dog you come across.  Be very careful with that trait.

I'm not a lawyer.  I'm a Sheltie person.  What I'd say is
1) Bring your older dog with you when you consider adopting another older dog.  Shelters will work with you on making sure they get along.
2)Mixing ages in the house really is never a good idea
and
3) Let that young dog go.  You did provide a good & loving home for a time and she needed it.  However it wasn't a good match or you wouldn't ever have thought of taking her back.

If it is a good rescue organization a consistent small monthly donation will go a long way toward smoothing over hurt feelings.  They never turn down a donor's cash and you love dogs so why not?  Don't ask for the pup back even with a donation.

I hope that helped!
Dave