Most disappointing and inept customer service

During December 2015 I did I migration on my line. As a result of this I was unable to purchase any data while the migration was pending and was thus forced to use out-of bundle data. I called and this was fixed and I received credit on my account for the out-of-data charges - thanks for that. But with me auditing my bill since I knew I was charged out-of-bundle I saw a R 99 charge for 500mb - I never bought this. Called 082111 they tell me someone CALLED in and ordered the data - I said it's not me and they log a query. Then I receive feedback the 500mb was credited to my account! I NEVER ORDERED IT! I call back, then they tell me someone called in AGAIN and ordered 500mb data, ANOTHER R 99 charge to my account. I ordered them to dispute this because someone somewhere is committing ***** on my account I NEVER ORDERED ANY DATA! They log another query and then all of the sudden the story changes and they accuse me of buying the data on the self-help service. I NEVER BOUGHT THAT DATA - I HAVE NO IDEA WHERE IT COMES FROM - even if I DID buy it, it's even charged wrongly: my 500mb bundles on my contract costs me R 49 and not R 99. They better get this fixed! I will go to the ombudsman!