Autopage
Can not get my GB

I have signed a new contract in May last year, CellC Straight Up 400 Prem Cons which is 400Mb 2GB per month as per Cel-C package at the time,
Autopage refuse to supply me the full Data as per package.
I have called their useless call centre many times, I was referred to the Mrs Najma, also.. she is not replying to my emails,
Can I sue them for? can i cancelle my contract? they must pay me for the missing data?

Thank you
Yossi