Terrible service

Been battling for weeks to get a refund. Service at Northgate shop shocking and whilst promised a full refund, still waiting. Have sent numerous emails to customer care without getting a single response other than “give us your ID”. Have written to the manager of the store and got no response. I’ve tweeted with them on Twitter and still getting nowhere. All I am asking is for a refund and a simple reply on my questions. Just pick up the phone and contact me!