@magur - Try this
Dial 1800-889-9999 from non Jio number. Select Language, it will prompt to enter non Jio number. Enter the same non Jio number you used to dial Jio customer care and the call would be transferred to a human.
Note: I don't have Jio number, never had one. Just tried above using my Airtel number.
Send PORT request, you will receive call from Jio
Call 198
Listen 1 or 2 min IVR
then select network problem
Some more options
Listen every option
then finally you get 9 option where you can talk customer support