Vodacom *****ing my airtime

For the past few months i notice that my airtime keeps disappearring, well this month i put my back up phone on flight mode just to see if my airtime will disappear again, well guess what it disappeared while my phone where off and on flight mode. Vodacom please explain how is this possible??? I want you to reimburse me. Its a shame that you steel from your customers. I think maybe its time to move my business elsewhere. I can't be taken for a ride each and every month. You should be ashame if yourself. Im ****ed as **** and very dissappointed.