How much does it cost to get finger sensor calibrated

how can my problem be solved

I tried that... When I started a discussion in forum they said that all the A50 devices has the same issue. someone suggested to downgrade the UI

I also had the same issue... and I visited the service centre regarding the issue... they said that I had a problem related the glass (they say that my glass is broken in the inner) give me an hope that it gets fixed... or will there be an update reg...

can you explain it briefly