Let's start with some basics of what you shoukd have done.
1. You should have created an accountant copy file for the CPA for them to work directly with during which time your prior year remains closed to you changing data before the close date. Your CPA would then send you a change fike to import any chnages they made. If your current CPA does not use quickbooks you should shop around.
2. You should have left the prior payment in place and made an adjusting journal entry in the current year. One offsets the other and deleting is not appropriate after the books are closed for the period
Therfore i suggest you recreate the payment with original date from last year. Then enter a journal entrynfor any date in 2020 that auits and that reverses the payment. The two will offset each other in your next reonciliation