Complaint regarding Jio Fiber free offer

At the time of purchase (1st April 2023) connection they told me that you will get 2 months free if you pay 12 months fee in advance. When i called customer care after 11 (Feb’24) months of uses they denied and said we dont have any such offer. I request them to remove my connection immediately however i have paid fee till 31st March 2024. They told me that you will not get any refund if you surrender your connection before due date. I said ok i dont want any refund. My connection was surrendered around 20th March 2024. Now i am getting calls regularly that your bill of 171 is pending. Customer care executives are rude and they have no sense of talking. I want to file a harassment complaint against the Jio Fiber. Please do the needful.