Awaiting phone

Took in my phone for the so called free screen repair. Then they tell me my phone failed their quality test and have to pay for them to fix it. When i argued that they must just fix the screen leave everything else, thet say it was not allowed. After a long argument decided to pay the amount. Needless to say every week is a different story on why i haven't received my phone back yet. At first they sent an sms to say that my phone is waiting for a part. A week later was told my phone was ready but never came, when i called to enquire, they say my phone is still waiting for a part. What is frustrating is whn i call no one can tell me the report on my phone. One weeek is ready, then the other they are still waiting for a part. They tell me they will get back to me and of course they never do. Going over a month now and still no actual news on my phone. All they tell you is they will escalate it to the relevant people. Till today they are escalating it to the relevant people.