Airtel India Apple Watch Series 4 Cellular Pairing problem

Pairs without an issue if I choose not to pair with cellular. When doing with cellular keep getting text from Airtel that says - "Hi, Your Smart Watch cannot be paired with your Smartphone as services on your Airtel number xxxxxxxxxx are currently restricted." Airtel says that there are no such restrictions placed. Voice and data are working fine on iphone XS max on this airtel #. If i pair without cellular and later try to add cellular it says on the iphone Apple watch App - "Your AirTel account is not eligible to enable cellular on your Apple Watch. Contact AirTel for more information." Airtel says all fine at their end.