Jio Fiber - Fake Promise by sales executive

Hi

My name is tahir my registered no is ********** i shave taken a new jio fiber connection
in june and the sales executive told me that there is some offer going on with new jio airfiber *+* pay for * month and get * month i have taken the connection and today just after * month i have got a bill of ***rs

when i called customer care they are saying no such offer

Sales Executive name is Chandan Singh his contact no is +** ***** *****

i want to register a complaint against him and want a strict action to be taken against him and want an proper on paper prove of the action taken

and want the solution for the bill amount i have got??