Legal action threat by tikona, asking bill payment for closed service

Hi Tikona, Billing Account Number : 131594628 User ID : 1119795006 Plane Name : ADBBM6M650 Howrah I was using post paid plan(ADBBM6M650) which I have stopped using and last few days of my last cycle I didn't get any service because I was requested for 'Discontinue the service' for UserID # 1119795006 which was 15 days prior of last date of my last billing cycle but I have paid full money of my last billing cycle. Same thing I have told over the phone about the 'Discontinue the service' from my registered mobile. My last date of my last billing cycle was 14-Apr-2017.After that I have not used and I have not logged in. After a month I have received a mail for bill payment for next billing cycle. After that regularly I used to received get 2-3 call per day for bill payment from Tikona which I have not used also I used to get mail frequently. Tikona's Advocate sent me a legal notice for pending amount Rs 1715/(3 times higher than my monthly plan) which I have received today(13-Sep-2017). I have mail proof which I have sent for closing service on 20-Mar-2017.PFA Why Tikona's Advocate sent me that legal notice for money which I have closed?