No need to worry bro. Just connect with customer care or tweet to Airtel Presence and update them with ur issue/concern....they will certainly help u with removing the channel activated by mistake , refund the money in ur account and activate the channel which u want.
Incase u call customer care and the executive is not able to help, ask him to forward the call to his floor supervisor/senior and i am sure the concerned official will address/resolve ur issue over the call itself