What should I do?

I am disputing a check that National Opportunities, a payday lender presented to my bank, and cleared. Unfortunately, the stop payment crossed, so that is how this transaction on their end was successful. Fortunately, I have funds available, so I didn't incur any overdraft charges from the bank. I have filed a dispute with my bank and the DFI. Should I also email National Opportunities? With the check they cashed my loan is paid in full, but I don't know if I should send a request for refund letter (I've paid about $525 for a $300) or what. I just got a call today from National Processing who said they were working on behalf of National Opportunities and I mentioned the last check had cleared. So I think at least that CA won't call me anymore, but I didn't tell them that I was disputing the payment with my bank.