Airtel — frequent increase in monthly pack rates without intimation

Under customer id [protected] in my name the monthly pack charges have been increased from 366 to 370 and now to 399 without any intimation. When customer care was contacted they have told that my mobile no is not correct. I requested to update my mobile no and it was reloaded. But it is pathetic to say that i received the message of removing and uploading the same no. I am not happy with the services of the company as the rates of same monthly pack are being increased frequently. If the rental of my present pack is not kept as rs 366, i will be forced to change the company.