Airtel - issue with billing and disconnection

i have * lines of airtel , * at home and * numbers at office. i raised a request for disconnection on oct **th for home number and got a confirmation that the request is received from the airtel team but while disconnecting, the airtel team has mistakenly disconnected one of the office number which was not in much use and hence i was not aware that the office number is been disconnected. i assumed home network is disconnected as i received a confirmation email. now airtel is harrasing me to pay dues of approx Rs. **** also i have been paying monthly rent on the office number which is disconnected how ever i stopped paying the rent from JAN and i got a refund of only JAN month cheque. airtel people are harassing me everyday to settle the payment and not ready to check emails and accept their mistakes.. already escalated to appellate team but no use.