First apartment

Well I finally made it to Malta in April. Made my way to my apartment. After meeting landlord and collecting keys he put the rent up €50. The following three weeks the rent whent up
He changed the contract four times. We agreed a price for the rent if €600 in uk and signed contract. Four weeks after moving in the rent had increased to €800 a month.

First take legal advice!
Alternatively, try telling him you are going to the Inland revenue to make sure the contract is registered, it has to be by law, because it almost certainly hasn't been and he is evading tax. He might be a little nicer then, though he may of course get even worse!
Any landlord of that type is probably never going to give you your deposit back anyway so perhaps find another place now you are here and just walk away from it all now.

Ray

When you say he changed the contract 4 times, was each version of the contract signed by both you and him?  If so, then he is in breach of contract.  When a contract is signed by both parties then it is a legally binding document for the length of the contractual period. Have you got all versions of the contract?  I would consult a lawyer.

may i ask why did u accept that if there was a contract in place? i would go straight to a lawyer, i personally dont know of one to suggest though.