Asus India — Asus zenfone max network issue

Address: Rajkot, Gujarat, 360004

My asus zenfone max in network issue but not solve my problem after 6 time visit service centre
But not a solve my problem
And my phone is already in service centre
Rma no. Ini6h60018
And i am also contact customer care 8 to 10 time
Chesh id is
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But not a solve my problem

And my second zen fone max is same problem but not a solve my problem
And phone is out of warranty
Serial number is sn:fcaxb7014570gfh