Don't give up and fight them all the way. Direct Bikes try to bully all into submission and think that by denying everything you will go away, the also try to hide behind their email which is the only way you can contact them. Following the various threads and comments on different forums this usually succeeds. They have to abide by the laws of this country which includes the Sale Of Goods Act and they cannot override your statutory rights, no matter what their contract or warranty says. The terms need to be fair and reasonable. If necessary take them all the way to the Small Claims Court, it will be worth it if you win in the end.