Absa refuses to close an account because of R1 uncleared from 5 months ago

I am unable to close a cheque account due to an uncleared amount of R1 from November 2019. This amount was for an account verfication when I signed up with a new insurer but for some reason it hasn't cleared and Absa refuses to close my account.

I really feel like Absa is using R1 to hold me at ransom, as I am still charged the account fee and they charge me for being overdrawn on the account, but the only reason it is overdrawn is because I no longer use the account and they refuse to close it.

I understand that an account can't be closed if it has uncleared transactions, but this transaction was from 5 months ago and no one can tell me how to get it cleared. Even the insurer who did the charge said that they don't understand why it is still there.