Continual Premium Collection on Cancelled Policy

Our business cancelled the insurance with MUA, at the beginning of June 2020, having been a client for more than 11 years. Our premiums have always been debited on the 1st of each month, in advance. Even though we properly advised MUA, with plenty of notice, the past 2 months' debits (July and August) continue to be debited to our account! Our business has now closed down and MUA still debit the account, effectively still *****ing money not owed to them! We have been repaid the previous month's incorrect debit, but it was worse than having a tooth pulled!!! What a lousy insurance company who doesn't give a hoot about their clients - I would've personally recommended them to others, but now..???