This could be an IT error. Your card was flagged by some program that swept over fraudulent or MS abuse type of accounts, you know accounts that don't generate profit but loses to the bank. This makes no sense otherwise.

If you are sure you have done nothing wrong I would suggest you send a certified letter asking for an investigation Usually people send these type of letters to the executive office listed. If this does not alleviate the situation then contact a friend who is a lawyer or go to small claims court.

You don't want an account closed by lender on your credit report. And you want your points back. You have done nothing wrong.