Chase Bank USA, NA Chase was stealing money from my account without my knowledge. Wilmington, Delaware

Today I received a letter from Charles Haug, General Manager of Chase Identity protection Services.  It informs me that "We determined that for a period of time, you didn't receive full credit bureau monitoring benefits as part of your Chase Identity Protection, Fraud Detector, or Credit Builder membership." 

They enclosed a check for $422.31 and gave a contact phone number to call for questions, which is 1-888-290-4681.

I called the number today and spoke with a hoarse sounding woman.  She immediately, wihtout my telling her why I called, asked if I was calling in regard to a letter sent to me.  I told her yes, and she asked for my customer number.  I gave it to her, and she verified I was to receive a check for the above mentioned amount because I had not provided authorization for the services I paid for, and that when three credit bureaus are not notified, the company issues a refund for my payment.

I have no recollection of any dealings with Chase because I know someone who had a bad experience with them in the 1990s.  I did not ask for the services I was being charged for, and for some reason I was never even aware I was being charged.  I think they are guilty of fraud and I want to know how to ask for an investigation.