Sent my iPhone 6 to quick mobile fix to get my iPh...

Sent my iPhone 6 to quick mobile fix to get my iPhone 6 front screen and rear fixed in November. I received the phone back at the end of November. Two weeks ago the front screen came apart and two components also fell out, their technicians had clearly not tightened the screws correctly. I sent the iPhone 6 back to them two weeks ago and heard nothing, I phoned Three days after they had received the phone by recorded delivery. The technical department told me they were fixing the phone. I heard nothing and Two days later after another Fifteen minutes waiting to get through I was told the phone was fixed and they were checking it before posting back to me. I was told this was at no cost to myself. The phone did not arrive and again I was told it was waiting to be despatched. After having the phone for Two weeks I was then told a customer care manager was going to phone me. This did not happen. Eventually we got to speak to her only to be told they hadn't fixed the phone and if I wanted them to they were going to charge me.
That means that they had the phone for Two weeks and lied on many occasions. This company are awful and I would never use them again.
If they had no intention of fixing the phone from the start they should have told us straight away and not kept the phone for Two weeks.