Bad Salesperson and months of conflicting service!

In Dec 2014 I exceded my 1GB databundle and wanted to get an extra 300MB to see the month through. I went to the Irene Mall branch and asked for an extra 300MB which I wanted to pay in cash (since it is a one time deal). The Lady helped me (but wasn't sure how my phone worked to activate the MB). She also said not to worry about paying cash since she will just add it to my contract amount. Unknown to me, instead of adding an extra once off 300MB bundle, she changed my contract bundle from 1GB to 300MB only. Not what I wanted or was aware of.<br> <br> The next month I used my data as usual only to be surprised a month or two later with a R1 034 instead of my normal R450. I contacted customer services the day I received my statement and have been in a battle with them since then. In one of the many conversations they assured me they made a mistake after an investigation since I paid for out of bundle data instead of the 1GB I'm entitled to and will credit my account with over R600. They even asked to give me a form to repay the money. Since then they have denied this and investigate it every month. I phone them every time I receive a statement and payment goes of my account. Still no joy!