Discover Credit Card Complaint

Discover Credit card department,

Bankruptcy Florida

Years ago an old boyfriend put my name on his Discover credit card. I have never used his card or paid his bill or received a statement. He has recently filed a bankruptcy. He has contacted me because on his email billing statement they have removed his name and put mine. When he called them, they told him, I opened the acct and put him as a signer and then telling him I called and had his name removed '', and then they wo n't talk to him saying it 's my acct. When I called them demanding they send me proof of where I signed to be responsible for his debt, they dodge the question, demand payment and refuse to send me this written proof. Can they really make me responsible for his debt? I am worried they are adversely affecting my credit score. Please help.