How much can you change on it yourself?
Your site seems to be showing up pretty well for your target location in Abergele, you are top in the google my places, up there in there twice in the top 6 results, once in a yelp listing then your organic ranking.
The problem that i reckon you are having is that Abergele is a very small place and there will be hardly any searches for window cleaners in your area. You need to check analytics for actual traffic before you make decision.
I target a much bigger area than your do and get very little from it, so with that small town youve no chance.
What you need to is change or add more areas that you cover, if you only work in that small town then there not much else you can do.
one thing i would say is if you are only interested in Abergele you might as well learn to build your own site on wordpress and pay a about a fiver a month for hosting. It would be really easy to rank with very basic seo.
The site you have is quite nice looking, but it not worth 78 quid a month especially since you wont get a return on that.
EDIT: sorry i noticed your site mentions, rhyl, prestayn, llandudno as well, these are bigger areas and would be good keywords to focus on, however your site only mention them once in a paragraph which wont be good enough to rank given that competion for those keywords is likely to be higher.
Depends what you can and cant change, i would have a page for each location optimise the seo for each, the usual page titles, h1 tags and meta etc. Im guessing you cant really make any proper changes though.