Sorry to hear that this is a bigger problem than expected.
Most of our customers are existing Media Center users, and as such they would have had an IR receiver already. We therefore did not bundle a receiver as standard. We have the option in our shop to purchase a receiver for those that do not have one. You may also find a Media Center receiver in a local shop quicker and/or cheaper. We would like to send the buttons over the radio link, but that would give an un-acceptable battery life on the remote as the radio would be on more, and use a lot of power. We are investigating our next design at the moment and we intend to provide wireless buttons. Not that that helps at the moment.