Many people did the same thing with payday lenders.
Often borrowing money at illegal rates and paying them back until they no longer could or refused to pay back the last one.

If you borrow money from a loan shark several times and pay the money back at illegal interest rates. The past has no bearing on whether or not a current loan is illegal or usurious no matter how many other similar loans you've already done with them.

The court can only rule on the legality of this particular loan. Is it by itself legal or illegal?