Some registrars charge ICANN's fee ON TOP of their normal registration prices. In this case, they are passing this cost onto their customers, so the customer pays the normal registration fee _plus_ the ICANN fee.
Dynadot, however, does not charge the ICANN fee to our customers. Our $7.99 prices are all-inclusive. This means that we pay the fee, and we do not pass the cost onto our customers.
Its not required that the registrars issue us a refund for .03/year for each domain name registered or renewed since July '06. Its solely up to them, besides you would probably get $3.00 anyway.