Okay buddy, if u find it wrong or u find this policy to restrict ur choice to add/drop channels on a regular basis or within a short duration then u can share the feedback with Airtel Digital TV ....if still unsatisfied just opt for another operator of ur choice which best suits ur needs. All i can say each operator has pros and cons so noone can always be completely satisfied .
I suggest u to wait for 15 or 20 days and then take a decision after seeing whether Airtel Digital TV rolls back this policy or if other operators too implement such lock in policy on their platform or curent status quo is maintained