Airtel — New recharge activated before the expiry of existing recharge thus providing lesser validity

I recharged my airtel number with Rs.719 unlimited pack on 11th September 2022 but instead of queuing up the new recharge until the expiry of the existing valid recharge (ends on 12th Sept 2022), the new recharge was activated instantly on 11th Sept 2022 with validity extended only till 4th Dec 2022 instead of 6th Dec 2022, and thus affecting the overall validity and making me lose two days.

I called customer care and the executive could not help with anything and repeated my complaint.

Also mailed the concern to [protected]@in.airtel.com, but they are more concerned about email that I am using is not registered with them.

This is plain cheating.