I have one Samsung tablet and one Samsung mobile phone. When I insert my Airtel SIM in tablet then it automatically sends one SMS to an unknown number, and when I insert the same SIM card into my mobile then it again sends one SMS to an unknown number. So every time an amount is deducted from my balance.
I don't know what is the problem and how to get out from this problem?
Is it a problem with the SIM card or with the mobile/tablet?