My services to be suspended

On the 01/04/15, I upgraded from Samsung s3 to tab Samsung. The agreed amount as my contract stated is 296.00. Cell C debited 448.00 on the 31/06/15. I went to cell c cape town branch on the 02/06/15 to query they said this is my contract amount. I showed them my contract but they could not assist me. I called in their customer service 140 and they told me the same. I've emailed copy of my contract so they may retify the mistake but nobody came back to me. On the 06/07/15I went to nedbank and paid the 296.00 and faxed the receipt and then I went to reverse the 448.00. on the 09/07/15 they sent me a message stating that I am in arrears with 152.00. Today they sent me a message that my services will be suspended.