Lost R900 airtime & 300mb in less than 12hrs

Today I woke up having lost R900 and 300mb called the MTN customer care line and I was told I was on the internet between 19hrs to this morning, Apparently on this day MTN reception was excellent that I possibly used an equivalent of 6gig yet my whatsap messages when I am in my complex take 5 minutes to go through. this is ridiculous as they cannot supply which website I was on . And they can only escalate this on the 13th of March my next billing date and as a client I do not know what happened to the airtime. This is **************** as I am still expected to pay my bill religiously . As per the consultants I spoke to and their supervisor there still is no guarantee I will get my airtime back . This is big corporates like MTN stepping on small guys and getting away with it and everyone there parroting about their bureaucratic system on no help to the client. I want an itemised bill and my refund of airtime and data ASAP. I question the purpose of the call centre customer care if you cannot get help. This is incident is ridiculous and should be treated urgently!!!