Battery change on IPhone disaster

Took my pristine IPhone 6S in to have the battery changed. Received phone back with indentations on the housing, a yellow line on the RHS of the LCD screen and could not hear a thing when someone phoned me or trying to listen to voicemails.

Took it back, told it would take an hour to fix. Left a cell number for them to contact me when complete. Returned an hour later to discover no work completed as the manager wanted me to explain my isuues to him directly. Bearing in mind he was in possession of a contact number and decided to waste my time, completely unphased about the fact that I explained we have a 2hr drive home once they were finished.

Battery changed at 11:00 in the morning. Instructed to not switch the phone on until it had charged properly for 4-5 hours. Discovered the issue at 15:30 in Ballito. Drove back to Gateway at and brought the problems to their attention at 16:00. Eventually left at 18:00 after they attempted to explain to me that they had only changed the battery and could not have caused any of the other issues. Had replaced the flexible connector to the speaker in the interests of customer service but could not do anything about the yellow streak on the LCD. Only after I explained that I work in the Electrical & Electronic engineering dept at a Large OEM and that I would be consulting with them did he admit that he had used spirits on the phone attempting to open it and it may have caused danage to the LCD. He can replace the screen, but is of inferior quality and will be broken within 2 weeks.

If you want to avoid frustration and damage to your phone - take it somewhere else.