Debit Order submitted AGAIN

Signed for pay as you go - SIM did not work until payment was made. Now I was informed on the 27th June my service would be cancelled on 30 June 2021. Only to find that today, they did another debit on my account. The response I now receive is that services take a month to cancel. And billing is in arrears - so SORRY no refund. Disgusting service - I can accept I did not cancel in May and June (thought they billed by usage) but now I must pay for another month - because they allegedly bill in arrears. No way - as I have said - on signing up - I had to pay before the simcard worked. And in April with all the public holidays - that they did not do a debit for - the service just cut and I had to pay by credit card to get it reinstated. NOT happy at all