Microsoft Zune Changed pass so I could not recieve my 10 credits per our agreement saying their system can't change back. Redman, Virginia

They changed the way I pay my monthly bill so I can't receive my 10 credits per month. I didn't change anything. All I changed was my credit card info. They say I changed to a cheaper pass so I don't get my 10 credits per month. They say they can't change it back. They also said they have had many intendances where this has happen to other people. They won't  give me phone support numbers or emails, I can't talk to anyone else.They won't give last names or ID numbers. They cut you off a chat with them and say you hadn't written anything in a couple of minutes. That is their way to get rid of you. You try to get back on and they say there are 19 people ahead of you. I have been with Zune Microsoft music for a many many years. I paid 16.99 a month. I have spent much time and money on my music, I am not well and my music is a big part of my life. Now they're doing this to me ,to make more money. I don't pirate music, I do it legally and this is what I get. They can't get away with this. Someone please HELP. I have copies of chats with them. Will A class action suit work? Aren't these people subject to rules of ethics and fairness? Will making the almighty dollar rule the day? I've tried to live an honest life, follow the rules and these big corps. take advantage of the weak.