From contract to prepaid no 4G on Iphone 6

I went from a Vodacom Contract to Vodacom Prepaid, with the switch I restarted my phone and for one or other reason that cannot be explained by any customer care operator I don't have any 4G in areas I used to have 4G on my Iphone 6. My 4G is checked on the phone, but since the switch I haven't had a glimpse even of 4G.<br> Do you need to be on contract to receive services like 4G?? I have spent hours on the phone with the call center, no luck for the last 3months. In order to use my phones full capability i will most likely have to switch to another service provider, since Vodacom isn't rendering the valued service on prepaid as with contract. Very disappointing.