Cell C’s appalling services

I’m extremely appalled by the services from Cell C, I set up a debit order which debits my account on the 25th / 26th of the month, for the month of May, they me a reminder advising me that they will debit on the 26th/05/2025 to my dismay, they did not now suddenly they advised me that I have a missed payment when I asked when did they attempt to debit, they advised me that it was the 28th of May which I did not agree to and they are not willing to waver off the charges yet the inconvenience was on their side in top pot that they are the most expensive service provider with so much of unprofessionalism, I’m very upset and doubt that I would ever recommend them to anyone I know