Email: support ticket, http://www.123-support.co.uk/
Telephone Number: 0871 230 9525 (9am - 7pm Monday to Friday. Calls cost 10p per minute from a BT landline.)
Address:
GX Networks Ltd
5 Roundwood Avenue
Stockley Park
Uxbridge
UB11 1FF

Other Useful Information

If you provide us with log in details to their control panel then we can transfer any domain name easily away from them to us.