Motorola Solutions — Imei number got erased

We have bought motog3 in may 2016. Within one month the imei number got erased. We went to the authorised dealer at secunderabad, telangana and got the software updated. There are two branches of authorised service centres one repairs the warrantied mobiles and the other one unwarrntied. The one with which workd under warranty redirected us to unwarrantied repair centre and by paying an amount of rs.650 we got our phone repaired. Again the same problem has repeated. This pinstrument is still under warranty. Can u replace this. Do respond immediately