Samsung — Video recording in M21 Samsung Mobile

Address:

733 Phase 10 Inner Road Phase 10 Sector 64

I have purchased M21 Smasung mobile through Amazon a month ago. I am facing issue in recording videos. stabilization of camera is zero during recording. Even 1-2mintues video recording, background color of recorded video automatically changes color like more grey, white exposure white etc. Camer autofocus not work properly . Even 1-2 minutes videos, always camera blur after every single moments, I have visited three times at service center for this issue.
First time, they said this is software problem and update software of my mobile, but issue still remain as it . second time, they said engineer will check this problem and QNA will be send to Company.one week passed, still not resolved my issue . After one week I visited third time to service centre, they said, have to wait 2 days . Our engineer will check and camera will be changed after check. In my home, I have three product of Samsung. But I had no idea, service of Samsung is poor, not even to average. I had never expected this service from samsung.
My humble request to samsung company, kindly resolve my issue if you are genuine . Don't kn inow .