There may be a few reasons for this:
1 – you had cookies blocked in your browser (as the affiliate link and banner sales are tracked via the affiliate username saved as a cookie so if cookies are blocked the sale doesn’t get tracked for the affiliate account);
2 – you forgot to use your affiliate link;
3 – you used another affiliate link (accidentally or by mistake) so the sale got tracked for another affiliate account.
Unfortunately, the affiliate commission is not refundable in all the above cases.
If you have more questions feel free to contact our affiliate support by submitting a ticket request.