Good day engineers in the house, my infinix zero X506 version 4.4.2 was poping up messages for 3 weeks to upgrade which i ignored,one morning my phone stopped working,i took it to phone technician,he checked and said the battery is damaged,new battery was installed but it refused to work,he tried to find lasting solution but it did not work,please can any body tell me what to do to revive the phone and make it start working again,am expecting urgent reply thanks.

Maybe he didn't install the battery correctly or touched something inside the phone.

I recommend you bring your phone to another phone repair shop and see if those guys can fix it.