Ask them for a written Adverse Action Notice. They are required to provide you the reason for any change in terms such as higher interest rates, lower credit limits, or turning you down for credit. In particular, if they pulled and used your credit report information in making that decision, they must disclose to you which credit report they based their decision on.
You can then request a FREE copy of that credit report to determine if there is any erroneous negative information on it, and use that report to dispute it through the credit reporting agency.
Keep in mind they may be reducing their risk exposure in this credit situation based on balances you have with other creditors. That is one reason why the bottom is not in yet in this cycle, as all the lenders reduce their lending and risk exposure.
