Vodacom just doesnt make sense.

Since when can you not buy Data with airtime ? I saw a deal on my Vodapay app, which was 18GB's of data for only R165. I usually buy airtime and then use the airtime to buy data, as it also gives you more vodabucks. Just to find out the i cant buy that deal with airtime, and can only use my Wallet or my banking app. I phoned through to customer service hoping they could assist me, but all i get told is that i must buy it directly from the app and not use airtime ? By all means if i was told beforehand that the deal is only available through my banking app, i would've done that. They cant even transfer my airtime to my wallet? Which also makes no sense as it stays money ? Like i dont understand how it works like that. Ive been a customer for literally my whole life, and its just a non stop struggle, and they arent willing to assist you either.