Beyond bad service!!

I am writing this letter asking Hello Peter to help me so that Blake & Associates can provide me with a paid up letter so as to clear my name with Cell C. I had a cell phone contract with Cell C, I then missed some debit orders and I was then told that I am blacklisted and that my account will now be handled by Blake. They called me and we arranged the monthly payments up until I settle the account which I totally understand. Now the problem is that I then settled this account on the 31st of December 2018. I then did a follow-up with Blake to provide me with a paid up letter by mid January 2019 and I was told that it was pending. I waited up until I did another follow-up by the end of February 2019, was told that an email has been sent to notify Cell C, I waited. I then went to Cell C store at Fourways Mall to enquire on whose supposed to provide me with the paid up letter..I was told that Blake & Associates should do so since they are the ones who are handling the account. I then wrote an email to ********** letting them know that this ''paid up letter'' issue is taking forever and it's blocking my credit plans. They then responded saying, ''they apologize for the delay. An email has been sent to Cell C regarding your paid up letter.'' this was on the 2nd of April 2019. I called again on the 4th week of April and still, I was told the same thing that an email has been sent to Cell C. Today is the 16th of May 2019 and I'm still told the same story that an email is sent to Cell C, it's been over 4 months now and I can't even qualify for car finance or bank loans due to this issue. I'm terrified and my life is a mess. Please assist me with this issue, I've tried over and over but I'm not getting good news