Cell C not taking responsibility for system error

I've used *147# to upload data on my phone for the past 2 years. On 24/05/2015 I loaded 25MB as I regularly do, but when I received the sms confirming data purchased, it showed 10GB. Despite the fact that I was certain that I chose option 1 for 25MB, I immediately contacted customer care, after which the lady advised me that it will be reversed on 07/06/2015 and that I should not use my data but rather switch same off. The reference number I received was #***. I contacted customer care on the same reference on 01/06/2015 and 03/06/2015 on which they informed me that the matter are being taken care of and someone will contact me the same day to confirm. On 09/06/2015 after no phone calls received from customer service, I once again contacted customer care who now informed me that because I used *147# to load data - there is no way same can be reversed even if this was 'n system error! And all that I'm told is that Cell C can do nothing and that the lady who helped me on 24/05/2015 was not supposed to tell me that same would be reversed and I should switch off my data! I also contacted Tsapiso at head office who confirmed the above and advised that I'm liable for the 10GB.