Vodacom worse service provide and a *****!!!

Vodacom have the worse service Ever!!!! I bought a 3gb data on Sunday the 11th August 2019 at about 11:40am by 2:40pm same day my balance was 1.4gb without even using the data,how is this possible???? I then try to call them the whole Sunday afternoon to no avail as the call centre number kept on saying they have high volume of calls and they can't take mine. I just hotspotted on my laptop for about 10 minutes and a gig got depleted,like how is this possible?????As a results my 3 gb data got depleted over a day??????? Again when I call the call centre it still says there is a high volume of call... Vodacom is a day light *****!!!!!! Bad service!!!!! To say I'm angry is an understatement