Beware adding extra data to Cell C inclusive bundles!

OK so I have been had by Cell C. We have a monthly contract for 20 GB of day time data. Which is usually enough. But March 2019 we ran out on on 30th March. Tried to load data on website but kept asking to 'complete the Captcha' but nothing on screen. So went to Kenilworth shop where rep helped me load 2.2 GB valid for 5 days at R100. Assured me this would be used first before inclusive bundle but guess what? Yep, used a few MB of the 5 day once off and then started chewing into inclusive bundle. So have lost virtually all the 2.2 GB I paid for. Went back to shop, the rep who helped me on 31 st March not there and the lady who was cant help........... Beware! There is no way to load extra data without running the risk of losing it unless: you add extra data for 30 days AND use ALL your inclusive bundle BEFORE the extra bundle expires. Makes no sense whatsoever. A nice con by Cell C and not what rep in shop assured me would happen.