Disgusted in the service I received

Poorest service I have ever received! They replace my iPhone’s screen, the next day I go back because the screen turned black and the touch screen didn’t work at times. The guy said I must come back the Monday as he needs to order a new screen as the one he put on my phone is faulty. He said they close at 18:00 the Monday. I said to him that I am working far and will only be at the shop just before 18:00. The Monday I left work an hour earlier and stopped at the shop at 17:30 to find out they are closed. I phoned the cellphone number on the board numerous times after a lady picked up and said I must come back again. I told her that I work far and I cant take off work to get to them and I made an appointment and they just closed the shop. Later when I went back to the shop the guy said he will replace the screen but I need to pay full price again. So I must pay double the price because they put a faulty screen on my phone after advising they will change the screen and just closing the shop after I had an appointment with them. I am disgusted in the service I received.