No one can resolve my query

Called rain on 22/06/23 and spoke to Fanelwa at 14:40 to update my card details, she said she cannot change and that I'll have to do it on my end. I informed her that her colleagues where able to take me through the process and only then she agreed to go through the process with me - at first she was not willing to assist me at all. She put me on hold and said she tried and she can't seem to change. Said it is a system glitch and said she will esclated to billing department and said they will contact me as soon as she send's the e-mail, when I asked about the SLA she said they will call me back before end of business today. She also promised me that she will call back herself the following day to check if they would have gotten back to me, till now my issue that started in March has not been resolved and I have not received any call from the billing department like Fanelwa promised.