Vitality rewards and call centre

I have been struggling with claiming my Vitality rewards 70% of the time since downloading this app when it was launched. I either get an error and cant open my reward, or I get the reward open but the system at Kahaui does not pick up my reward code. My friend has exactly the same problem. So I decided to finally contact the call centre to complain. I was on hold for 16 minutes to get through to the consultant. I explained my problem and got a ref nr *** and a promise to call me back with feedback. Now almost a week later I am still waiting for that call. I sent an email yesterday to complain via email, still no feedback. I am shocked at the service and difficulty to reach someone for help in this matter.