What type of tenancy agreement do you have? What's the length of the agreement? Have you reached an agreement with the landlord over arrangements for your temporary absence?
Your tenancy agreement is a a contract between yourself and the landlord. You agree to pay rent for the accommodation. If the landlord can't provide you with the agreed accommodation then your choice would be to enforce the contract or claim breach of contract.
If the current accommodation is uninhabitable then it would be reasonable to expect the landlord to offer you alternative accommodation of a similar standard and you would continue to pay rent.
If the landlord refuses then you can claim breach of contract and consequential loss.
In your circumstances you probably also have a case to sue the landlord, the neighbour or both for the damage caused to your property.
From your posting it sounds like the landlord expects you to pay your own accommodation costs and pay him for accommodation he doesn't provide.
See the
Shelter website or try the Shelter Helpline on 0808 800 4444.
It might be worthwhile making an appointment at your local Citizens Advice Bureau. They have contacts with housing specialists who can help you clarify your rights.