Bad Service as always!!!!!!!

I have been having an issue MTN from last year december when my contract was up for a renewal, I first to MTN Mall of Africa where I got the worst service of being told the system is down after 2hrs waiting. The next day I went to MTN Greenstone and finally managed to get my contract renewed and because I got two new devices, I then had to struggle for 2 weeks to get those activated and registered. I evenentually got that right until I realised that one of the devices was assigned a number belonged to another client. From last year since successful registration of the new number, I have been receiving calls and SMS(some with very personal information of the previous owner) e.g when he makes withdrawals and when money is deposited into his Standard Bank acccount. I get all his phonecalls to a point where I've been blocking all calls coming in for this person. I logged a call in December already explaining to MTN that this client's informaion is being compromised by the recycling of his number and deleted his name against my number but all I got was a reference number confirming that this will be dealt with. This shows the level of unprofessionalism at MTN that even when something that is as compromising of another client's data has not received any attention till today with no feedback from them.Today alone I've received 6 calls that are meant for this person, I dont know what it will take MTN to remove Rodney from my number so I can only receive calls meant for me on this number