Telekom cheats me off data

<p>I am on Telekom prepaid . And for the past two months it has been taking all my data in a short space of time. I have all my apps closed and the background apps closed . However it still eats my data . For example today I bought a 1gig and in an hour I was already at 500MB with only replying to watsapp messages. I have plenty of messages to prove this with my data finishing so quick . I have called Telekom more that two times . I even opened a case but nothing . Can you please help me I'm very frustrated. </p>