Putrid service

I purchased a cover for a phone on 23 November, it was incorrect and I logged a request for exchange/refund and received another one on 10 December and it was still incorrect. Called in to speak to a manager but was unavailable, left a message with my details for a manager to call me but no one calls, but I received a fancy email stating that my request had been received and a manager would call me shortly. No manager or staff have called me regarding my problem. Today is more than 3 weeks since original purchase, I have also bought a cover from another company and I want a refund...!!!!