Vodacom *******

So I recently been getting charged for advances when my data runs out. So her is my problem I did not asked for this advances it just been charge when my data runs out. And on top of that you get a service fee as well. Now my actual problem is i did not give you permission to randomly start doing this or charging me.I dont want the advance. And where did it just start out of nowhere. My brother then told me I could switch it off and I did that but it is still charging me. Now my thought is how much ppl is vodacom just automatically charging them for advance that they dont really want and would actually be fine without data or airtime until they put it in them selves. It feels like an abuse of power from vodacom and taking advantage of ppl and clients that dont know better.This feature needs be be regulate better.