How long can the card issuer take to resolve my billing error or dispute?
The card issuer must send you a letter stating that it has received your billing dispute within 30 days of receiving it. The card issuer must complete its investigation within two complete billing cycles of receiving the dispute, which generally means two months, and cannot take more than 90 days.
If the card issuer determines that no billing error occurred, it must mail or deliver an explanation of the reasons why it believes that no error occurred.
If the card issuer determines that a billing error occurred as claimed, then it must correct the billing error, credit your account with any disputed amount and any related finance or other charges, and send a correction notice to you.