QUESTION: Did This Happin IMMEDIATELY after receiving the phone back? or did the device work properly for a couple weeks before noticing the issue?
NO: if the phone was working properly for a bit after the repair, it is highly likely that something else is causing your second issue.
YES: if the phone immediately has issues, then go in for a consultation at your local repair shop. any technician worth their salt will warranty a problem that has occured due to their neglegence.
QUESTION:: Did your phone work prior to the screen replacement. (Could you operate the phone in a normal manner, and read the battery % after the damage occured to the device?)
NO: There is no evidence it was due to tech error, and was likely caused by the impact of the device. boardwork is likely required, and i suggestgetting it to a SMT specialist.
YES: It is high probability that it is a tech error. take it back to your repair center for their quality warranty immediately. the longer you wait, the less likely they will be inclined to beleive it is from them.