Account overcharge and 500MB data disappeared

My data ran out and I received an sms stating that I had run out, an options list covered the message and I did not know how to get out of it, so I selected no.1 - I was immediately billed for 10G to be used in 14 days, which just cannot work as I am permanently on Wi-FI. I called immediately and spoke to an agent who successfully reversed the data from my account along with 500MB of my newly allocated data. Unfortunately my account has not been credited with the charge of R310-00.