Contract plan has fallen away. But now they want to retract my data while im still paying

Ive been a telkom mobile contract holder for two years now, they plan I am on (smart plan) has fallen away, now they want to reduce my data from 1gb to 150megs even though im still pay R199 pm. They wont even allow me to migrate my contract to an existing plan (free me). Ive tried migrating to a special they have for the free me 1gb and p10 lite. But they wont allow it unless I pay for both contracts simultaneously and then I cant keep my number.