Extremely unprofessional service Vodacom Fibre

I had my 20mb fibre installed by vodacom in May and noticed my usage was extremely high despite the fact that we do no online gaming or we dont dowload content. Its is used for browsing, a little bit of streaming and work. I called vodacom several times and i was given by a supervisor and an agent their personal email addresses to resolve my data usage problem. I have sent them several emails which to date have been ignored, i logged several queries which fell on deaf ears, today the 1st of June at 3pm my data usage was at 14gb in a few hour's ,how is this possible VODACOM please explain to me and give me a detailed balance.This is really poor customer service when queries are not responded to and the fact that data charges are so high one would think that would atleast offer customer support, instead they open and close queries without any explanation and do not solve the problem, so its back to square one after every 48 hours.