Who should I report this to?

Hey, I've recently left my work due to who I thought was "a friend of mine" throwing racist remarks aimed at my boyfriend.. My employers are well aware of this as it was another one of my work colleagues that he's been racist towards also. I reported and he wasn't allowed to work with him again (same as her) just changed on to different shifts. We are Care Workers in the community for Old and Vulnerable adults..One thing on our contract was:Racist abuse will not be tolerated! Doesnt seem much is being done about this..So I wonder who would I go to to make a formal complaint on why this company is hiring these sort of animals?