Airtime and data deplition

I had R94 and 250megs whatsapp data and 250megs of all in 1 data. I switched my phone off because I had a low battery. When i switched my phone back on i had no airtime, no whatsapp data and no all in 1 data. I lodged a complaint yesterday and the 1st consultant told me she can't help me and cut the call without any help. The second consultant told me they would load a case and sent me a case number. This morning I received an sms stating that they had done an investigation and I should call them for the details. When i called them they told me that I had used all the airtime and data which I don't understand because my phone was off they then told me that they couldn't send me the breakdown of how the airtime and data was used via sms. I requested to speak to a manager they 1st told me that the manager would only be in at 9 and the manager Barret Parter would call me as soon as he arrived. I only received a call from the team leader hlengiwe who told me that the manager is too busy to speak to me. I them asked for the CEO details because no one was helping me and she refused. I need someone to explain how my data and airtime got depleted when my phone was off.