Voiding a payment of cash

SUGGESTED

Hi, We received a payment that was directly deposited into our checking account. The deposit appeared in our account on 12/31/19. When I went to post the payment, I posted it as a cash payment against their invoice. The problem is, I got distracted and I forgot to change the receipt of payment date back to 12/31/19 and it posted to 1/8/20. The system will not let me void the cash payment or at least I can not seem to figure out how to. Is it possible to void a cash payment? I just want to re enter it with the date of 12/31/19, to match my bank records.

Thanks so much!