Samsung j7 duo me One ui 2 ka experience kaisa hai update karne ke baad koi problem toh nhi aa rhi please bataye

Hey samsung team, my friend in  your service centre for the issue of network problem in samsung a30 . Now they changed speaker of his phone and speaker is damaged what should my friend do? They said that they never changed speaker. 

after September there is no update on Samsung Galaxy j7 duo 

My mobile dual volte feature is not working