Global Visas is a trading name of Immigration Compliance Services Ltd (Company No. 05688454) which was incorporated on 26/01/06. (Interestingly, despite the firm's website declaring that it was founded in 1996, the Companies House register states that there was no earlier name). The company's registered address is Salisbury House, First Floor, 5 Cranmer Road, London, SW9 6EJ. That's the same address as is given on the websites of both Global Visas and IXP Visas.
The globalvisas,com domain name was registered on 31/07/97, whereas ixpvisas.com wans't registered until 25/10/12.
As has been written many times before here, there is NEVER any point using ANY visa agency (with an obvious exception being where an Embassy has outsourced its visa application process to an accredited agency, as with the Russian Embassy in London). Visa applications through such agencies don't get any special treatment and it's not difficult to make a direct application yourself.