http://www.holidayroomsdirect.com/contact.asp

They also come under the name of Sports Tours Direct Limited.

A 192.com search didn't reveal much and a google search reveals a few companies operating from that address and from it, they appear to use numbers beginning 01302 366xxx.

Neither holidayroomsdirect or Sports Tours Direct Limited appear to be listed on BT's DQ.

Internet archive from 2004 reveals an 0870.

Unless anyone else can think of something then you have the following options:-

1. Try some numbers around the range 01302 366xxx
2. Email them (not from an obvious uk email address so something like hotmail.com) and just say that you have tried to call them from your location but as your are abroad, they don't allow connection to a UK 0870 number so do they have a 01x number that you can ring them on.  Don't go on about the costs or anything otherwise they'll likely realise you are just trying to avoid paying the 0870 costs.

This company seems very protective of any underlying geographic number they might have. Holiday Rooms Direct is the name for Sports Tours Direct Limited, also at the same address in Doncaster. Companies House check doesn't return any further details. "08707 55" is allocated at BT, of which there are obviously many entries in Doncaster...

Anybody else able to shed any light on this?

Looking through the listings on 192.com, 01302 388 007 for Microkool Ltd at Fitzwilliam House caught my eye. I've just tried 01302 388000 and it has an answering service on that says that the offices at Fitzwilliam House are closed. So this is probably reception/switchboard and others will follow....