Airtel — mistakenly recharge to airtel number,

HI,
on 12th July I have recharged an amount Rs 99/- to my mobile number - [protected] by mistake, even though I have valid unlimited pack which is expiring on 13th July.

When I called Airtel customer care number 121 on 13th July and requested to reverse the recharged amount Rs 99/-, they are not ready to do the same and abusing me by saying the mistake cant be taken and reverse cant be done

Request to kindly check and take necessary action on Airtel company.

Thanks.
Prashanth