Refund my R300 or data

On the 25th of September at 14:00 I temporarily increased my spend limit to R300. On a normal basis (if they would check the history on my account in terms of temporarily increase spend limit) they would see that I normally purchase R299 however on that day it said that: "you cannot purchase less than your previous limit increase amount thus I purchased R300. I immediately went to the next option where you purchase the data and when I selected my normal amount of 5gb it said you have insufficient funds. When I called in at 14:05 I was told I used it up on Internet and my data was on (knowing I have been making this transaction the same way since last year when I opened the contract and never have I had this experience) now I must pay R300 for something I didn't use. I spoke to Nomxolisi at 14:40- after I was told that I must call back after an hour so that their systems update and so that we can see the updates (the first agent told me they don't do call backs and Nomxolisi said they do). Nomxolisi confirmed that I allegedly was on Internet where I was not I requested to speak to the supervisor, where I was placed on hold for 10 min only to find out that the manager was busy this was Luthando-the manager. I requested for the manager to call me and till now I never received a call. I urgently request a detailed statement to show me where I used the Internet on what that would cost R300 within 2-5 minutes while I was on a call with their self service. My request is for either the R300 to be removed from my statement or for my 5gb to be loaded.