Telkom LTE 50 GB DATA running out

Hi, we have a contract with Telkom for our LTE 50GB a month and for some reason we are running out of data at alarming speed. According to our data report from our server we only used 20.2GB from the 01/04/2016 to 20/04/2016 but we had to load another 20GB in the last 5 days. This doesn't make sense at all. We already changed the router and sim card but the problem is still ongoing. The closer we get to the end of the month the more data is gone, now almost to 4-5GB a day. Tried to phone Telkom but no one has any answer to our problem.