Not difficult to find some info.
Search Google for "London Gazette" and first result is their website
www.gazettes-online.co.uk, where the Contact Us page gives the following info:
Quote:Contact Us
For information or queries on advertising in the London Gazette please contact us on 0870 600 3322, or e-mail us at london.gazette@tso.co.uk.
The postal address is:
The London Gazette
PO Box 7923
London
SE1 5ZH
To order a subscription to the online Gazette or paper copies please telephone TSO Order Line on 0870 600 5522, or e-mail us at subscriptions@tso.co.uk.
The e-mails addresses there make it clear that they are part of The Stationery Office
www.tso.co.uk, and their front page shows a link to that.
Confirming this, the TSO's site (at Contact us > Customer Services) gives the same 0870 number as above.
But Contact us > Customer Care gives some geo numbers; now, these are in Norwich rather than London, but could call them and (i) complain about the 0870 number, (ii) ask for a real number.
Quote:Complaints, comments and complimentsWhilst we aim to deliver excellent standards of service to all our customers, we also realise that at times you may be dissatisfied when something has not gone well.
We welcome the opportunity to be able to address this and investigate the matter for you.
If you want to make a complaint, comment (or make a compliment!) about our services, you can do so in the following ways:
call +44 (0)1603 696972
email: customer.care@tso.co.uk
fax: +44 (0)1603 696458
textphone +44 (0)870 240 3701 (for customers with hearing or speech impaired disabilities)
write to:
TSO
Customer Care
PO Box 29
St Crispins
Duke Street
Norwich
NR3 1GN
Hope this is of some use.