roaming and non-roaming data bundle

Had a 3Gb data bundle for my pocket router which worked fine at my holiday home (which is why I got the bundle in the first place) - it was running out and I topped it up with a 10GB data bundle. Took the router on holiday and all was well and I used about 3/4 GB while away. Got back to my holiday home and can't connect to a network - after a long time on the phone with the technical people I was informed that the top-up bundle was "non-roaming" and could not connect to the local Vodacom network. (the original bundle was a "roaming" bundle and that's why it worked). Because I bought it on line no one could do anything about switching it to a roaming bundle and one answer to a reference query was as the bundle was in use I would forfeit the data if it was deactivated. Now nowhere when I topped it up did it mention non-roaming, in fact the shop where I got the original bundle did not even know that there was such a thing! So now I sit with 9.25GB of data which is totally useless to me and no one seems to be able to assist me either after three stressful calls to the call centre and technical support! How does Cell C sell a bundle which is non-roaming without some sort of indication telling the customer what they are getting - yes I've checked the T&C and nowhere does it mention that there are two different types of data bundles.