VAT Refund - explaining on bank imports?

As some of our revenue is from sales to EU and outside EU, and most of of Cost of Sales is UK, we are often in a refund situation. We have HMRC approval to submit monthly on this basis. Just setting up on Clearbooks.

Our year end is end April so I needed to set up opening balances incl VAT Control. My March return was a £12,000 refund so I entered it as a negative amount in a bill coded to VAT Control - to get it into the creditors accounts. My April return was a payment of £400 So my 2 entries in opening balance as Bills are: +£400 bill - VAT Control -£12000 bill - VAT Control

The issue now is I have a bank import to explain including the £12,000 refund from March VAT return.
This is showing as a Receipt and so it won't prompt me to match it against the "minus £12000" Bill unpaid.

Should I set up HMRC as a "customer & supplier" and handle the transaction like a sale / revenue receipt? ie create an invoice coded to VAT Control and match the bank receipt against the "invoice"? That sounds not right - but is it just a way to get the amount into the account with the correct CR/DR into the VAT Control account? If that's the case do I void the Bill and start with an invoice instead?

This is a regular thing so as well as fixing the current transaction I need to know how best to do it going forwards. I haven't yet done the first monthly VAT return on Clearbooks (and it is a payment rather than a refund this month) How does Clearbooks handle it as a refund - does it generate an invoice at the time of "Create VAT Return"?

The £400 Bill is fine - on the bank import it has flagged this up to match the £400 payment from the bank to HMRC and so mark the bill as paid.