Change Of Address Of A Gift Subscription!!

I changed the address of the person that the subscription was being sent to on July 13, 2015 conformation #339116707. I then receive a card in the mail in September stating that the magazine is being returned to them and would I please correct the address. I believe that I have already done that. I was told after numerous tries to get any service, that the address of the person the gift subscription was being sent to could not be the same as mine, me being the person that paid for the gift. This is absurd. I paid good money for the subscription and have missed issues since July and I think I should receive the back issues that I have missed. I was put on hold and music played in my ear until I gave up. Please help me with this matter as I am becoming very disgusted with your service. All I want to do is change the address.