help need..

i bought g2 from shop in used
I check model and with imei thought internet .It show D802 and 32gb
it running perfect but when I updated it to lollipop via PC suite it touch working improperly ,network disable, imei unknown and showing 10gb only
So I open *backcover of* mobile*and it*writing D800
So What I do now.......
*I flash back to KK but problem still same