Automated debit order date change! Very frustrating

I’m very disappointed with rain and how they changed my debit order date from the 25th to the 15th and now I get debited on the 15th every month when that bank account has no funds and I end up getting disconnected from the service. It’s been three months of asking for this to be changed to no avail. Once again I’m disconnected from receiving the internet service because my account needs R619. I’ve been asking for the date to be moved from the 15th to the 25th since Jan and I’m not winning. I have expressed my disappointment at the lack of assistance as now I pay the full amount every 25th and the service gets cut on the 15th. Which means I pay for a full month and get two weeks of service . I didn’t move the the date to the 15th rain did and now it looks like I don’t manage my account well because ‘the system’ moved the date on its own after I expressed that the 15th doesn’t work for me because I can settle the bill on the 25th. I was promised that this would be resolved yet here we are again this month with no service and a chatbot that tells me the same thing ….about sending a payment link. To say I’m frustrated would be putting it mildly.