Dispute between tenants and landlords

Landlord can't stop or disconnect tenant's electricity and water supply. You should approach court and get restored same.

You can approach the Rent Control Board and if the board does not take action, then file a case in court.

To my understanding, the contract is very much in force notwithstanding rental agreemnt. it is illegal for the landlord to to deny water and power supply.

However, the tenants also should not try to force the things by non-payment of rent etc. They should approach the competent court to compel the landlord to provide the amenities he had promised.

The landlord cannot disrupt the basic amenities for whatever reason. 

You can file a suit for permanent injunction against the landlord to restrain him from indulging in such illegal activities and to follow due process of law if at all he has any dispute with the tenant. 

However it is fault on your part to pay reduced rental amount,  your act may be considered as willful default for which you can be evicted. 

Even though there's no written rental agreement,  it can be considered as an oral rental agreement because the payment of rental amount regularly clearly establishes the landlord tenancy relationship. 

You can consult a local advocate and proceed as suggested. 

There is no written rent agreement, how would you like to demand / ascertain / establish your claim(s) ?

Relying upon oral agreement, it is just an assurance.