SHOCKING DATA BILL

I am a red VIP contract holder (unlimited services) for years know. Suddenly I got a shocking data bill of R16 000-00. I did not use Vodacom data except when I use Google maps etc. for a few minutes. At my home we got uncapped WIFI from Telkom. We phoned on several occasions but nobody want to help us, the only answers we got is, pay R8000-00 then we will connect you again. The other answer was if you use WIFI he cellphone use both, cellphone data and WIFI. Nothing change on my side is for years that I got my contract as it is, use it together with die Telkom WIFI this is the first time I am billed for data use. I am not the only person the guy Mr Chris Lindeque who worked with me got a bill of nearly R9000-00 for data use.