The number you give seems to be for other companies as well as Breathe Internet.
It is for
Business Unmetered, a service operated by Vital Data, a global eBusiness Solutions Innovator.
Billing - (Mon–Fri, 0900–1800) 0870 7473970
Customer services - (Mon–Sun, 0900–2000) 0870 7473970
Business Unmetered Customer Services
Vital Data
Victoria House
64 Paul Street
London
EC2A 4NG
However there's this
link to another company,
UK Fantastic. If you look at their website, you'll see the similarity in the design and phone numbers they use.
UK FantasticGiacom Dial Ltd
Commerce House
Paragon Street
Hull
HU1 3PW
Tel 0870 740 7777
Fax 0870 740 7177
Another internet account is with
WHSmith which says it's in conjunction with Tiscali.
However, that seems to be at odds with the contact details if you have problems -
if you have any service issues with your ISP account with Breathe/Vitaldata, please contact Breathe.com at:
Billing and other support 0870 747 3699 and 0870 747 3970