Although I can't speak for TopBucks here, as someone who wri-tes affiliate software for a living I can tell you that this may not be a miscredited sales problem at all.
In one example where this was happening, we determined it was caused by the tour tracking system. Say a user goes to Affiliate 100's website, clicks the link to a site, and then leaves. Later they go to Affiliate 200's website, click the link and go to the same site. They're now tracked as an Affiliate 200 referral, but because they'd been to the site from Affiliate 100 the coo-kie which tracks their referring URL is already set to Affiliate 100's coo-kie. The fix in this case was to flush both referring URL and affiliate ID coo-kie when the supplied affiliate ID doesn't match the coo-kie.
And before you jump on the use of coo-kie, note that the Affiliate ID should be pushed around the tours in the URL somewhere, and that the hahahahahahas are only used to make sure you get credit if they come back on their own accord.
I would suggest you send an email to support@ letting them know of the issue.
Buran
Edited to remove 'hahaha'