Airtel
Auto dialling some number and charging for it

My mobile no is 9650430826. Today morning I found some number (9160920092009) dialled from my mobile at 6.55AM and about Rs 50/ deducted from my prepaid balance.

I have not done this call. How did this happen and what protection airtel will give for such auto dialled calls and will they recredit this Rs 50 and odd in my balance back again.

Sometimes, the mobile is totally silent both for outgoing and incoming calls, but charhes Rs1 for every outgoing call that was unsuccessful. Can these be rectified or I be advised the reason for the same?

Thanks

V.Thyagarajan