Very frustrated!!!

On 16/12/2014 I purchased a Cell C (R299.00) 3GB SMARTDATA using FNB online platform. The data expired on the 15/01/2015. But I purchased the same Cell C (R299.00) 3GB SMARTDATA on 14/03/2014 at one of the stores which I used until it was depleted. I spoke to Mohammed Ebrahim (27/01/2015) from Cell C to enquire why the two data are behaving differently. He referred me to FNB that they should have provided me with terms and conditions. I took the matter with FNB who said CELL C is responsible for the terms and conditions, they are just a 3rd party and providing a platform. I need an answer as to why the data expired within a month. Feeling very frustrated with level of service I'm getting!!!!