Business Central - unable to post purchase invoice with negative quantity (purchase return)

Hi, we noticed a vendor invoice for Jan 2021 was posted with different items and we over paid. (this invoice has been paid). So I tried to create a new PO with negative quantity (I added the original items with negative quantity and added the actual items/amount) that showed a negative total equivalent to the over payment that we will be receiving from the vendor. But sBC doesn’t allow and show an error. Are we missing something? Or is there a different way of processing this in BC. Appreciate your thoughts on this.

Description Context
Amount must be negative in Gen. Journal Line Journal Template Name=’’,Journal Batch Name=’’,Line No.=‘0’. Purchase Header: Invoice,xxxx61

I tried to create purchase credit memo directly from the posted purchase invoice (that has already been paid)

Invoice xxxx26 is closed. The corrective credit memo will not be applied to the invoice.
Show applied entries | Skip | Create credit memo anyway

I am not sure if we can try “Create credit memo anyway”. Appreciate your thoughts on this.

I tried to create a new purchase ccredit memo by copying the posted invoice. but there is another problem. How can I reflect purchase of new item, for e.g. i am returning 2 qty of sku1 and getting 7 qty of sku2. also sku3 purchase amount was wrong. I can adjust the amount in the sku3 or could I be able to return the whole thing and either 1) create a new Purchase invoice and post it or with the credit memo itself I can add a new purchase item by adding another line with negative qty of Sku2.

when update the credit memo itself by adding new item with -negative qty (that actually the correct sku and amount) the credit memo amount matches to the vendor overpayment amount! But I am not sure if this is the correct way of doing this.

Generally if you over paid and will be getting money back from the vendor, I would suggest using Charge(Item) lines to records the overage. Create an Item Charge named something like “Pricing Adjustment”. Create a Purchase Credit Memo and add the line for the Charge(Item). Enter quantity of “1” and set the unit price as the amount to be returned. Then assign the item charge to the original purchase receipts. Post the credit memo. This should revalue the original receipt and create a debit balance on the vendor account which you can apply the repayment to.