Cell C and NDS credit Management are useless they dont want to unbar my phone nor provide me with a paid up letter

Biggest mistake ive ever made in my life was taking up a contract with Cell C. I was rentrenched and couldnt make payment for 3months next thing im handed over to NDS credit management who are also other *********** people. I paid my account on full as they requested and now they refusing to give me the paid up letter. Cell c is telling me to contact NDS when i contact them they tell me contact Cell C. What sick game are they playing with us ??? As for their agents they place you on hold for over 10minutes basically waiting for the line to drop on its own. They transfer you from one agent to the other and i basically called more than 10 times and requested to speak to a manager but no one bothered to transfer me through to one. I request for feedback from the cell c management team ans should i not receive any assistance from them in the next 24hours my next step is going to the ombudsmen ans involving a lawyer because wow im tired of their pathetic service. My details are as follow: *** email : *** or *** best time to call 13:15/10:00. I await your prompt response!