Faulty headphones losing faith in apple

I purchased a set of wireless apple headphones they worked great for 2 weeks until one of them would only work intermittently. I decided to take them in hoping they could be exchanged. I was told to wait 7 working days at it needed to be sent from the gateway store to jhb for assessment. I was eventually contacted and told I could collect my headphones as they had been repaired. I collected them and they worked for 3 weeks or so only to find out they have the same problem plus the case now only connects intermittently. I have taken the headphones back in and told to wait 7 working days. I find this unacceptable they must be replaced or I want a full refund !