Disgusting "service" from cellc

I loaded airtime to purchase a WhatsApp bundle. I never have applications running in the background, I clear them nothing less than 5 times a day. I then checked balances and everything showed zero. When I phoned the customer "care" I was told my apps running in the background had depleted my airtime. In a matter of minutes? Then to top it of the operator still puts the phone down on me! Cellc successfully stole my airtime, and yes I am prepared to open a case of ***** and theft for R30. This is 1 customer not prepared to take it lying down. When I tried to lodge a complaint on line I get told my cellc phone number is invalid!? I have been a cellc customer over 12 years already, very disappointing, absolutely shocking!