Adoption Issues

My husband and I adopted a 2 y/o lab/shepherd mix on 4/6/18. The dog was initially living in Texas then transported to Virginia in February 2018; the same rescue organization has branches in TX and VA, and they both coordinated his care. I had asked before adopting him if he had any significant health issues other than being overweight and was told no. We took him to the vet the day we got him and found out he was heart worm positive and has been since at least since December 2016, as he tested positive for it in June 2017 and it takes six months for the test to come up positive.

We adopted a cat on Sep 2016. We also signed a contract that said we would fulfill his medical needs, and if for any reason we were not able to, they would help us take care of it. The manager of the adoption center had offered to take him to the vet since he was overdue. She finally came the other day and told us she would take him to his appointments. Two days passed by and she never returned him and she did not reply to our texts or emails.