plain green loans and one click cash

First I want to thank everyone for all the good information on this forum, it has really helped me out. I started with four online payday loans and found out on this site that they are all illegal in north carolina. I followed the steps outlined and have received two pif from two of the lenders, However, plain green loans and one click cash, both of which have been paid more than the principle owed over three loans, have both responded that they would settle for the principle remaining on the current loan but will not credit overpayment on previous loans because they were seperate contracts. I resent them emails saying that I had overpaid them and requested the accounts closed and pif. So far, after a month has passed, no answers or additional emails at all. My question is,can these illegal lenders report to the credit bureau and is it likely they will send to collection agencies, as I have seen posts on here that people have been contacted by cas as much as two or three years after defaulting on the loans. I did not request a refund of overpayment, just a pif. Thank you for your help.