You have to check the lease contract which you have signed with the landlord. You should have your copy of the contract (another copy is kept by the landlord).
Is there a clause in the contract that explicitly said that the rent can be increased while the contract is still in effect?. If there is no such clause, then the landlord cannot just increase the rental amount. If the landlord wishes to increase the rental, then he/she should wait until your rental contract expires, after which he/she has to offer a new lease contract with the new rental rate specified. Then it's up to you to sign the new contract or not. But until then, he/she has no right to impose any increase in the rent while your current lease contract is still in effect.
You can complain to the nearest police station in your area. They have people at the station who deals with such matters/disputes.
Note: There is exception for utility bills (electricity, water, garbage collection, etc.) whose rates are always subject to change depending on the utility companies' rates.