Can I claim a refund as well as compensation

Hi all, I recently had my flight cancelled to Freetown from Brussels. They offered me an alternative flight with a code share airline but they denied me boarding for no reason and could only offer an apology. We ended up ditching the trip and they put us on a flight back to manchester.

I have received £520 compensation but as I was unable to go on the trip, due to being delayed by what would have ended up being 4 days, am I also entitled to get a full refund for the outbound and return trip?

Thanks

Edit: the flight was for march 2026, brussels airlines, originating in manchester UK, connection in brussels and then onto freetown. Return flight was Monrovia to brussels and then back to manchester