No one knows what to do.

I had a contract with Vodacom a while ago and then got contacted from a person in the accounts department saying that I had paid too much on the account and that they needed to update details and refund me the extra cash and that someone would get in touch with me at a later stage - about a month or so went passed and I received a call from Vodacom yesterday, unfortunately I missed the call. I returned the call and went through to accounts and then told them someone tried to get hold of me - gave my ID number and they couldn't tell me who or why the contact was made. So I asked to be transferred to the dept that made the call - transferred me to upgrades ( No Idea why ) then I spoke to a woman and told her the same story , she didn't know why obviously, then I asked to be put on to a supervisor or manager so that I could give him/her the info, they could find out whats up and then call me back and let me know. I was put on hold for a long time, and then hung up - it shouldn't take more than 10 mins to get a supervisor on the line . Please contact me and lets get this resolved? I cant believe how much the staff don't know, and how to handle such situations.