A few ideas/questions for you:
1. Have you tried adding a phone number on your home page without the spaces? The front page on your website only includes the phone number WITH the spaces. It might look odd, but you could try putting the phone without spaces into your footer, perhaps near your copyright or the address.
2. Have you tried updating your business on Google? Updating your own GMB profile can help you appear in results and make sure Google isn't confusing you with this other similarly-named company. https://www.google.com/business/
3. Also I took a peek at your search results and when I checked your business on Google Maps, your phone shows up with spaces but also with a +44 code in the beginning. I wonder if that could be part of the issue as well.
Hope one of these ideas help!