How to claim maintenance back from builder

The builders had made an agreement at the launch of the project for a consideration including a maintenance clause is also mentioned for a tenure of three years at a specified rate per Sq ft and a corpus fund, which will be paid to the Association when it is formed. The builders had enforced to pay in cash the agreed rate before the registration. We are compelled to pay the agreed sum without terms and condition of the maintenance, as our EMI had started we hurry to occupy our flats to save from House Rent payment. After occupying flat we came to know the Builders had collected the maintenance only to the extent of his share. Besides his maintenance is very poor. We brought to the notice but builder is not in position to here us. We had formed the Registered Association also and asked to transfer the Corpus amount but he is not transferring the fund.