Galaxy S6 Support and replacement

I sent my phone in for screen replacement after cracking it round about 17th July 2015 and was told it would be ready 10 working days later I then fetched it on the 30th and only had switched it on once I had bought a cover and screen guard. Only to find the back button was pushing it self the whole time and freezing. I then took it back the 2nd of August and said it was important because it is my work phone and I am self employed. They said it would be ready before the 7th. I had received a call on the 8th-9th saying they were waiting for parts. I then called back 3 more times after that being told they still waiting for a part. On the 30th I called and was told it was ready then went and Sat in traffic for 2 hours only to be told my device is not ready and that an order had been placed on the 26th for a new device which would arrive in 2-3 weeks, was given my old phone and an update was available which I then did and it then softbricked itself. I then called on Thursday the 17th September and was told to call exchange claims and give them 8901 which I did and was then told it must still get 2nd approval what kind of service is this that a person has to call to find out what's up?