Top up data ******

I am on a LTE 100G monthly with Webafrica. On 25th May 2018 I realised that I was not going to have enough data for the month so I bought a 20GB top up for R250. I used approximately half of this between the 26th May and 30 May 2018. Suddenly on the 1st of the month when my allocated data was received, my top up data is at 0% but on usage on my regular data is sitting at 12522MB (webafrica's own records). How on earth is this possible?? My regular usage sits at an average of 4000MB per day. So basically what I assume happened is that my top up data usage was transfered to my monthly regular usage and the 20GB I bought and paid for has been ******. I tried sending a support email to Webafrica which I see has now been deleted with no answer. I then tried calling them but I get through to people who tell me that according to the portal I never used the top up so they don't know.... I have checked the usage and I finished my 100G on the 26th of May, yet there was further usage, so obviously I used the top up data!!!! I want this rectified or a full refund. Your choice.