Making JE is the error. You don't Make JE; that is avoided for anything where Name are also used. Not for AR, AP, banking, QB inventory, QB Sales, sales taxes, or QB Payroll. Not for Credit Card.
Double-Payment is From Whom, To Whom, for What?
Your error here: "My entries where debit checking acount and credit expense account."
That is supposed to be Bank Deposit. You are describing you Double-paid a Vendor? That would originally have been Write Check or Pay Bills. Did you get Refunded? A Deposit to Banking = Got Refunded.
"Do I need to reverse acount payable as well"
Never using a JE. If you Overpaid the bill, you already have negative AP. That's another reason not to make More entries.
If you paid the bil and also issued a Check, then you need to know if you put the same expense on the Check as the Bill = entered the same data Twice using two different methods.
And since the year is Closed, will they be refunding you this year, or did you want to show the Correction is dated in 2018?
Right now, you are working too hard and going to make it Worse.
