Motorola Solutions — hanging issues in phone. imei number is [protected] job sheet no. soin[protected]

The calling app hangs, sometimes caller's name isn't flashed on the screen.
There's a problem in camera launching during whatsapp and snapchat also.
Ive been to the motorola service centre many times and wasted hell lot of my time but they didn't provide me with any solutions, they always have an excuse or the other, they didn't even revert back when i sent them the video of my phone being hanged.
And now they're asking me to again visit the centre and i know it would just waste my time for one more time, they even kept my phone for a week to check, and they sent me back by saying the phone doesn't have any issues and then I sent these videos too. But no help offered but asked to visit the centre for something again which will lead to more wasting of my time.