Bad Service and Arrogance from Team Leader

I called ********** on 08/03/2019 for a change of D/O date to the 31st, spoke to Wendy (14H56) and was advised that all is sorted, instead it was never done. I called again on 26/03/2019, spoke to Boniswa (17H10) and related the same enquiry, she promised to send her Supervisor an e-mail to give me a call back, to date I have not received that call and yet, no change on debit date. Called on 17/04/2019 and spoke to Louise (17H18) to change D/O date to the 31st, yet again promised its done and again, still debited on the 25th. All these conversations I have records of. Called today 26/04/2019 and related my frustration to Innocentia (14H42) and requested her to call the Supervisor for me. Supervisor (David Mapokane) took the call, assisted in giving me information on the system to prove my facts and advised that I should send him the bank statement reflecting the bank charges when I reverse the D/O for the refund. All was going smoothly until when I asked for his contact numbers which he refused to give but only gave the e-mail. I specifically advised him that I want a line where I can call him on regarding this and not his cell phone, still maintained that he doesn't have any. I asked for his Managers number, he refused bluntly stating that he does not know his Managers line, even when I said I will send him an e-mail and in the interim, he should ask his Manager for his contact number as he failed to give me his, he still refused. Now I wonder why is it such a mission to get a contact number for escalation, more especially after the service that I received on a simple request. This is such a disappointment and utter arrogance from a person who is supposedly a leader of a team. I'm wondering why I even bothered to renew my data contract, but I'm definitely sure that I will be cancelling the other contract that is debiting from the same account as it is running on a month to month.