Inefficiency to resolve queries

My account was **********ly upgraded and the issue was reported to Vodacom with the required documentation. An investigator was appointed to investigate and he contacted me to let me know that this was actually a ********** upgrade. He was going to advise the billing department to reverse the debits to finalize the query. After numerous attempts to contact the investigator on his mobile,I decided to go to Vodaworld thinking that this issue will be resolved in my presence which was not the case. I then went back to Vodaworld 2 weeks later for feedback and spent over 3 hours with the consultant. She promised me that the issue will be resolved and I then requested my account to be blocked until the issue was resolved. Till to date I haven't received any update from Vodacom until yesterday when I was called by Debt collection company saying that Vodacom has handed my account to them to collect the outstanding amount which I owe Vodacom.I then called Vodacom and I was told that there is no ***** department to my surprise and I was then connected to the billing department, the lady that I spoke to said she will put me through to the manager and waited over 10 minutes the call dropped