Contact page gives:
Second Floor
Sussex House
London Road
East Grinstead
West Sussex
RH19 1HH
lowcostholidays.com is a trading name of Lowcostbeds.com, which is registered in England no 4371920
The website also says that its name was previously "Lowcostbeds.com". There are four unverified entries for LowCostBeds:
Low Cost Beds (LowCostBeds.com) 0870 066 8899 01256 314530 Sales only
Part of Lowcost Travel Group
Low Cost Beds (LowCostBeds.com) 0870 017 1001 01256 314530
Low Cost Beds (LowCostBeds.com) 0870 066 8899 01342 305644 Customer services
Low Cost Beds (LowCostBeds.com) 0844 477 0080 0800 1116270 This number canalso be used instead of the 0871 number for lowcostbeds.com if booking through teletext holidays.
A check of
BT Phonebook reveals:
1. Low Cost Beds.Com
Tel: (01342) 410682
Sussex Ho London Rd, East Grinstead, RH19 1HH
2. Low Cost Beds.Com
Tel: (01342) 316053
Sussex Ho London Rd, East Grinstead, RH19 1HH
3. Low Cost Travel
Tel: (01342) 302532
Sussex Ho London Rd, East Grinstead, RH19 1HH
The local code is 01342 which matches one of the numbers in the database. That's not to say that the others aren't suitable alternatives.
Try them and see what you find. Please let us know how you get on; what works and what doesn't (and why) as it will help me to list the numbers for others to use.