Consumer Redressal

Dear Sir/madam, This is in reference to the mail received from airtel regarding the payment due of Moble No 9717273567. The said mobile no (9717273567) I was using when I was in Delhi. In April2013 I was transferred to Mumbai. I hold my no for one month and after that I have taken on new Airtel Connection in Mumbai circle (from you Chembur Relationship center). Before taking New connection on 20th may I have made a written application for termination of my old(9717273567) connection as my billing cycle was 24th to 23rd in every month. Along with the written application I have also wrote in 121@in.airtel.com on 21st may for termination of my Delhi Connection(9717273567). Payment due for the month of May13 I I made payment in 7/6/13 and after that also they did not terminate my no and raising the bills. Now they are written me that they will take legal action on me and send a legal notice asking for Rs. 1858.64. Please advise what to do? Rgds, Rabisankar Mishra 7738103883