Putrid service

Firstly vodacom takes my airtime when I make no calls nor did I send any sms'. I have data so it cannot be because I browse the net or used any social media apps. I then called the call centre to find out why my airtime gets taken as this is not the first time this has happened and I am on hod for 30 minutes without any response. This is the worst service I have ever experienced and it's disgusting.