Categories Sharing Slugs

Hi all,

Having a bit of a problem with a WordPress concept I am trying to get working. In theory the idea should work however it looks like WordPress has its own ideas, im hoping someone else has come across this issue before as I feel its quite important when trying to use WordPress as a full CMS system.

So I am creating a niche database / directory of businesses serving specific purposes around the UK, about 3 different types. For SEO and easier management I have created duplicate categories with the parent of each being the type of service. Please see below for an example.

Service Type 1 > County > Town
Multiples of these are made to cover all towns and counties required.

Service Type 2 > County > Town
Again multiple ares made but the towns and counties are the same as before but under a unique parent category.

Now one of the main reasons this has been done is for SEO and Usability purposes, I want my links to be structured in a very logical simple way. For the first parent category this works perfectly and as intneded for all. The URLs display as follows:

https://url.com/service-type-1/county/town/

That is exactly what I want for all following links with the service type changing creating a unique URL. Instead when a new service type is added with duplicate counties / towns I get the following URLs:

https://url.com/service-type-2/county-service-type-2/town-county-service-type-2/

As you can see this makes the URLs more confusing and ugly to both user and search engine.

I have tried to manualy change the Slugs for all the “bad” categories manualy but have not been allowed to do so.

If anyone else has come across this issue and has managed to solve it please can you provide some help? Also if anyone has any advice or ideas to try that would be great.

Much apreciated
Ludz~