Jio complaint: Deficiency of service namely not provided international roaming service but charge with a bill of RS.520.31

I am having sim no.919945079334 issued by Reliance Jio. Based on media advertisement switched my tariff plan from prepaid service to postpaid services for my sim no.919945079334 after paying appreciate feesdeposits as well opted for international roaming.
After reaching United States of America, the above mentioned sim could not be operative even though my residence was equipped with ATT internet connection. i.e. at 66 N Boyle Heights, Mountain House, California, 95391.
I lodged several requests to Reliance Jio consumer care Department. In spite of rectifying the connectivity, passed time by giving funny advises. Being frustrated by their inaction, I requested them several times to suspend my international roaming facility. After prolonged correspondence, they discontinued international roaming facility but charged ₹ 520.31 for the disputed period which I am contesting.

I could not enjoy any international roaming facility for my sim no.919945079334 in addition underwent agony and frustration. Finally, the said sim is inoperative causing much inconvenience to me.
Kindly redress my grievience and restore my prepaid facility for my sim no.919945079334.
Thanking you,
Yours faithfully,
V.Nagaraju.