Closing your account: Credit card

I had a Fit Mastercard account serviced by Continental Finance Company. I received payment reminder emails regarding my account, but I never received any email or written notice informing me that my credit card account would be closed. I later paid the remaining balance in full because I intended to continue using the account. After making the payment, I discovered that my account had already been closed. I believe I should have been notified before the account was closed. If a notice was sent, I never received it. The only communications I received were payment reminders, which led me to believe the account remained open and available for use after I brought it current. I am submitting this complaint because I want the company to explain when the decision to close my account was made, why it was made, and how and when they claim they notified me.