Jio — Postpaid conversation

I have took a prepaid connection ([protected]) years back and my brother is the one who using the sim. He is currently overseas and working in merchant Navy. I have reached out the palarivattom jio centre for converting this prepaid connection to postpaid. I already informed the person I 1st talked with that this sim is now not in Indian and presently at Dubai. He handed my case to another person and that person proceed with the postpaid conversation and last he told me to call to 1977 and enter the 5 digit pin i received on my alternate number to activate the voice and data service and I informed my brother to do the same. But when he tried he was unable to make call as he is not getting through. I contacted the customer care and the customer care executive told me that he can only activate the service from India. If that was informed before the postpaid conversation i would not have opted for the postpaid conversation. Now I'm stuck in between prepaid and postpaid. And unable to connect with my brother. Kindly help me to rectify the issue asap.