Confused about debt resolution payments???

Would love to be able to get ahold of someone but it’s either disconnecting the call or taking hours of Christmas jazz music to try to speak to a human 😁

I’m on a repayment plan for defaulted student loans. I just made two payments using my debit card, but I just got a letter in the mail stating I need to send in a check for the same amount I just paid. Does anyone know if the amount I paid with my debit card counts as payment of my repayment plan, or does the debit card payment I made just count towards the entire 20k of student loans?

Basically- do I also need to send a check in in order to count towards my repayment plan so I don’t get in trouble?