Poor attention to detail

I have a contract with Cell C and when I took it I asked them to put me on debit order. It has been 3 months now and they haven't achieved this and instead I've accepting these mandates at least twice now. In both instances they haven't done that. First time I picked this up and call them to confirm and they said they didn't and they will re-do it however I must pay directly. I told them my challenge with this but I did it. Second month I assumed its all done and on the 6th of the next month I went ahead to use what I had in my account as my budget is tight. Apparently it was still not done and they expected me to pay cash again and I said I don't have the money they can rather move this debit on the last month of the 24 months. None responsive all along as I was speaking with the agent who was helping me to get the phone instead they went straight to block my line and insisted that I need to pay. At this stage I am in CPT for work and all this affected a lot of my work related matters. I needed to make a plan to borrow the money to ask them to open my account. It felt like it was abuse of power to me, while they are the ones who are wrong as they didn't complete the process of debit order which I tried twice. No accountability on their side as they know they can just cut the line. Very dissappointing.