they have a Polish speaking solicitor
There are many such companies. You can find adverts in any of the Polish language newspapers or websites for Poles in the UK.
they helped me with my claim
All solicitors in the UK operate to the same guidlines.
Here's a link to The Law Society, which all solicitors are members of - you can use the site to find a Polish speaking solicitor nearest to where you live.
Another option is The Citizens' Advice Bureau. It is free and independent and offers Polish language services. I recommend them.