*****-up on premium payments to Guardrisk

I took out gap cover with AlexForbes well before my retirement in 1996 and paid their premia monthy by EFT ever since. Then in April 2020 I noticed a second premium deduction through a debit order that had never had my authorisation. I then dealt with a very arrogant and unhelpful person who answered their phone who told me that they only accept debit orders for payments. The excuse was that they do not otherwise know who has paid them, which sounds ridiculous. I complained about the situation in writing, had some form of apology, with a refund for the duplicated payment. Subsequently there has been another duplicated debit order deduction, and after discussion, I called a truce with them, agreeing that the debit order may continue after my over payment has been allocated to the following month. The mess continues with an incorrect deduction for June and none for July. All this reflects poorly on those responsible for these matters and provides proof for me that debit orders needed to be avoided like poison. Why is it that I have all this trouble with Guardrisk and from no-one else who gets my monthly payments as listed recipients through my on-line banking