Dishonesty and unfair treatment to customers

I have been trying to get the Vodacom call centre to assist me with adding my banking details for my Fibre debit order from January this year, however they keep promising me that I will receive an sms after 24 hours confirming that my bank details were updated for the debit order. It’s been 4 months now, no sms came through, and this issue is affecting my credit score, which Vodacom cares less about. Treating customers fairly is very important, but to Vodacom, they aren’t willing to put the customer’s needs first. I even called yesterday for help but a call centre agent promised that she will call me at 12 to 1pm yesterday to give an update but no one has ever called since. Please can a manager intervene on this unprofessionalism and unfair treatment, before I escalate this matter to the relevant powers that be.