No replacement Defy oven after 7 weeks of continuous phone calls

Have been struggling for 7 weeks to exchange my Faulty Defy oven that I bought at Game. Very frustrating as there is no customer service, been phoning 3 times a week and have to follow up by myself every time and still no replaced oven! I am at my whits end and don't know what else to do to get help. Ref nr 764975