You are indeed on cabinet 21 however this is located on Farm Hill Road; around 2.5km from your property.

http://goo.gl/maps/ALUY

So unfortunately, as the checker indicates by not showing any FTTC availability at all, that its too far a distance for FTTC to be provided. Openreach will simply not provide a service at this distance, so no ISP is even able to submit an order unless the checker was to show some availability

Sorry!