Airtel — bill not generated for my airtel no [protected]

Dear airtel,

I have been using my this no since november 2011 and from 11th june 2017 i'm using thus no on international roaming @3999 pkg. I got my june bill on right time which i have paid. However my july bill have not been generated yet after several follow ups and got a sms on 21st august that my bill is 9000+ amount and on 22nd august got another sms that my bill is 11000+ amount. I have proper tap on my usage so my july bill can't be 9000 or 11000.
Kindly help me resolve this issue.

Soma