Vodafone India — received an email saying bill due and filed case against me after deactivating my postpaid account

Address: Pune, Maharashtra

Respected sir/mam,
I had deactivated my vodafone postpaid account 4 months ago for number [protected] and i received an email saying that i have not paid bill and need to be present in lok adalat for the case. I already had paid my bill for that usage and it has generated bill after deactivating my service.
Please help me and deactivate my service as soon as possible