So initially my phone jack had to be replaced because i couldn't hear the sound clear in my headphone it kept making noises. Than ask them to replace the sim and sd card tray which was broken with one that i brought online. After taking apart phone doing what i asked the phone would randomly shut down or stay on the Samsung galaxy logo. They than blamed the sim/sd tray saying it was faulty(the one i brought online.) they And also wiped the data telling they need to rebot it. They than said buy one of ours sd/sim tray which i did, the same problem kept switching off. I left my phone with them and am worried they charged be £50 (£20 for jack replacement £10 to put my sim tray i brought online and £20 for their sim tray). When they tookapart my phone i think they damaged it causing to switch off plus the sim tray wasn't fixed probably kept saying no sim sd so they didnt even fix probably. I have to see them tomorrow any advise or anyone know what the problem is?