Istore Canal Walk false advertising.

I signed and paid for a promised deal at Istore Canal Walk branch and had not received this deal upon my contract being debited. The deal included 10GB of data for the first 3 months. After multiple store visits and phone calls- no solution has been made, instead the staff telling me the problem has been ‘escalated’. It’s been 3 months and I still have not received the data. I’ve also now spent extra money on data that I shouldnt have needed to spend. I feel ****med.