Data disappearance

I bought 5 gig data from telkom, I didn't even download or upload anything and next few hours later my data is depleted . Now I have to pay for something i didn't even really used. Calling the call centre is also useless because they not helpful I spoke to a lady and she insisted i did use my data the agents kept telling me my apps used it in the background. which I know didn't .

I feel like now that my contract is coming to an end I am being ********** every month. I pay 2x more than my monthly install is monthly.

I was sent an email with data usage and no one phoned me back to explain how to read the spreadsheet. very bad poor service from telkom.