Breach of Conract

I have taken a cellphone contract, with Autopage during the course of October 2015, with my contract I do receive my free minutes and sms's, I should also be receiving 500mbs data per a month as well, but I only receive 100mbs data, I have queried this problem to the Autopage call centre on numerous occasions and they only give me reference numbers for my calls and tell me that my problem will be resolved within 7 working days, up till now nothing has happened, my last call was logged in December 2015 and my reference number: 939595, since then nothing has happened, this a violation of the agreement that I signed, your staff and especially your call centre is pathetic, you guys are intolerable, you sign people up to contracts and you breach them there after, which is absurd and disgusting.