It’s not possible to reserve paricular numbered pitches on club sites, Col, or even to reserve a HS/grass pitch. All you can do is book a serviced pitch, an awning pitch or non-awning pitch.

It's strictly first come, first served and you select from those available of the type you have booked.

The only exception is the reservation of pitches for the less able bodied by contacting the warden.

By arriving together, you stand a better chance of getting adjoining pitches.

Personally I think it ridiculous that there should be any problem changing booking from serviced pitch to none serviced on arrival assuming site was not full. In fact I have made the change on arrival myself about 5 years ago having booked a serviced pitch in error.