MTN prepaid... dissatisfaction

Im a prepaid MTN. Have been for years but this may be the last straw! I have bought 4x R180 vouches and 1xR60 voucher this week alone! Within minutes of loading my airtime, it is depleted! I called MTN as was told, that I’m using it on my data but I doubt I’ve managed to use R780 in one week on the net when I usually use 1GB in two weeks. It’s outrageous!!! A ****! I’d love to know where my moneys disappeared too.