Why my network not connecting properly after the recent repair?

From past 3 weeks i am not audible to my callers and so i went for a fix. The official apple service center technician suggested their is no fix for this you just need to replace the unit. So i tried with local store guy and he said he can fix it. on April 24th 2018 he replaced the entire microphone strip. But since two day's i am facing network issues and battery drain issues.

Is this is due to the new strip which he replaced? If so what should i do now?