When a tenant signs a Tenancy Agreement with a landlord, he/she is bounded by the following covenants:
1. To pay rent
2. Keep the premises in good repair
3. No unauthorised alterations
4. Not to commit waste
5. Not to sublet
6. Allow access to landlord or potential tenant or buyer to view premises.
7. Pay all other rates, utilities etc.
8. Not to cause nuisance; and
9. Use the premises for its permitted purpose;
Under points 8, of the tenant's covenant, causing nuisance may include abusive behaviour which is in breach of the Tenancy Agreement.
What you can do is to do lodge a police report should the situation escalate. Uttering words with deliberate intent to wound the religious or racial feelings of any person is an offence under the Penal Code Section 28.
Hope this answers your question.