No service from Cresta or MTN technical

21/04/2016 renewed my contract and increased data as I was suddenly being charged for excess use for first time in 24 months. On Tuesday 26/04/2016 visited Cresta outlet again and in frint of consultant checked and I had 754 meg data. On Thursday 28/04/2016 it was down to 524 meg. It was hardly used. Tuesday 03/05/2016 visited Cresta to check why. Raised ***. No response received. On Tuesday 10/04/2016 called Cresta Left several messages for Victor . Was promised he would return call. At 16h00 I eventually called back and got hold of him. Was told my ref closed without response. Promised he would follow up and advise within 2 days. On Friday 13th ( 3 days) get a call to advise could still not explain but given new referance and told he would call me by Tuesday 17th. We will wait and see. I no longer trust MTN and believe they abort data purposely and send sms's suggesting you are out of data in order for you to buy more. No wonder they are no longer the biggest provider in Africa