Data share, but no data available

When I heard about the mtn data share, I though it was great. It would solve my problem with data running out, but now it seems like I have even less data. I had 30GB anytime, and I played games, downloaded music, watched youtube, google a lot of things to use all the data before it expires. So I got the mtn data share simcard on contract. Well, it has been 2 months that I received 20GB anytime data each month. But every month my 20GB anytime data runs out faster than I can check my balance. Calling mtn does not help either, since the only answer you get is sorry you do not have anytime data left, only the promotional data which cannot be shared. The promotional data lasts the entire month. I have checked my usage on my phone. One day it says about 200 to 300mb used, then 10GB on one day??? I am so frustrated with this issue that was suppose to make things easier. I would not renew my subscription