If you're not using Steamwatch with Steam, then chances are 90% your Steam downloads will not count because Steam will not be downloading from WebAfrica's Server.
Thing with Steam is, it downloads from whatever server it can find, the ONLY Steam downloads that counts towards Freezone are when Steam is literally downloading from WebAfrica's Steam Mirror. The only way you can "force" this, is with Steamwatch. So yes, if you're lucky , Steam will download from WA and it will count towards Freezone, but you can't rely that it will happen every time.
BUT, Webafrica also clearly stated they do NOT officially support Steam+Freezone [because they have not been able to find a way to force our Steam clients to download from WA servers , from their side]. So, it works "unofficially" with some tinkering from your side, but WA is no longer using this is as a selling point. So if Steam downloads ain't going off your Freezone, then WA most likely have no obligation to refund you...
Now the second catch is, WebAfrica's Steam Mirror does not have all the content, or at least there can be a delay between what is on the USA servers and the WA servers. This implies that even if you did force Steam to download from WA, it will not find the content and you will be forced to download from the USA anyway [which again, will not count towards the freezone] .