I do not know a lot about UK word usage in cleaning services but I can throw in my 2 cents.
First, when I go to your page, it seem cluttered. I get lost in your home page and I am overwhelmed with the information. Do you need menu bars on the top and the left of the page? I would get rid of the menu bar on the left hand side. I would move the information below the yellow buttons for "020 8240 8630" and "Instant booking" to another page. I like the top of the page, it is crisp. This may help your people stay longer.
I am assuming that in the UK like the US, that people don't really care about "your company" they want to see what it will do for them. I noticed that most of your pictures are of your equipment or clean rooms and you use "we" and "our" a lot. If you look my site http://www.maidtoshinecleaners.com/
you can see that we try to talk about our customers as much as we can and we use pictures of people enjoying themselves. You may want to change your H2 at the top of the page, I did not even read it because it was too long, it never caught my eye. This may help people to stay on your site.
I am sure that you are aware, but http://www.google.com/trends/
is a great keyword tool. When I analyze your page it shows that your top key words on your site are: 1. Cleaning, 2. Service, 3. domestic, 4. tlc. Those all seem good, however I don't know what words are good where you are. Your 2 word key words are: 1. tlc domestic, 2. 570 269, 3. carpet cleaning, 4. 269 sl. These do not seem so good, I don't even know where the 570,269 is coming from.
Do you know how long your ad words people are spending on your site? We use http://clicky.com
to track this, and our average ad words visitor spends 2 minutes and 43 seconds on our site with an average of 3 clicks. We also use this to remove our competitors from seeing our ads and costing us money.
I do not know how long the site has been up, looking at whois I see it was first created 2007-05-29. I also see that you have a google page rank of 0/10, not good. However, your alexa rank is 4.4 million which is not bad. Your page authority is 30/100, which is not bad. What is your organic search ranking? I tried to see what you look like at http://www.google.com/adpreview
under "carpet cleaning" I do not see your website.
I know you are in London, so I am sure that it is a tough market. I am also sure that the ad words expense is large.
Hope some of that helps, best of luck to you. Feel free to nit pick my site too! It always needs help.