MTN Retentions Department (No service)

MTN Retentions department is the worst service, you cant get hold of anyone there as you hold on for 30min here 40min there to an hour with no one picking up the phone. I have contacted a few branches at malls whom is also saying that they cant get hold of the retentions department (does one call that service?) I am trying to cancel an account that was opened on my name **********ly but I am not getting any service and now my outstanding balance is increasing by the day due to no Service from MTN. Every time you ask the call center to speak to a manger then there are excuses