****ed customer by Spec savers

Round about the 13 March, I went to Spec Savers to do my specs. Received a call that they were ready, I went there the following Monday but I realized that I cannot see with them so I took them back the Thursday of the 22; Dr Siya redo the tests and realized something was wrong I really could not see, so he sent them back to the lab. I went back the following Thursday, 29 March to check if they are back, they were not back from the lab. I went back on the 7 April , still they were not back from the lab. I went back last Wednesday, 11 April still nothing. I havent been given the reason why I still havent received them. According to them, their SLA is 7 days but now am in my 4th week still havent received. Of coz the medical aid has already paid them, there is nothing I can. Even when I go to them, they will tell me that they will call the lab, God knows if they really do it