Airtel — misguided and false commitment by customer care leading to losses

I had requested for mobile number porting. The customer retention team of airtel called me and informed me that they would offer me a better deal at international roaming (Rs 2500 for 30 days to south africa). All i had to do was to convert my number to prepaid and contact customer care to get the pack activated. However after moving to prepaid the customer care says there was no such commitment made. I have all 3 interaction id numbers and can share if required.