Debit order issues

I joined rain on the 25th of December 2022, no issues with the service when on. My debit date was auto set to the 25th, service was cut on the 26th.I get paid on the 28th so the debit dit not pass, called Rain, was advised that they could only offer a debit on the 25th or the 1st. I said okay, please switch to the 1st, by this time the debit had bounced 3 times from the 25th for each day until passed on the 28th. Was then advised that the debit order date has been changed to the 1st, okay so the 1st came two days later, was debited again, i reversed payment for the second debit. Was advised that i needed to pay the second debit or revert my debit date back to the 25th which i opted for. So, Rain, please explain, I pay my service each and every month since i joined, yet my service is cut every month for non payment from the 25th until the 28th when my debit clears, i also incur penalties 3 times each month for when the debit doesn't clear. I lose service for 2 days each month.I pay each month, yet my service is cut each month for 2days. Rain, please explain your logic????