Supertech Group - Pre EMI stopped by Builder

I bought Supertech Hues Flat, on subvention scheme, specially because it was " EMI starts with possession". If possession date was to get delayed, Supertech was supposed to pay pre emi. Now, the possession date is still very far, Supertech has also suddenly stopped paying Pre emi, asking the customers us to pay for the same, saying they will make up for the interest amount one would have got from the bank against that amount. This goes against the whole subvention scheme planning- which works in converting current rent money into emi, because one would have their own flat to move into. Supertech is not responding to any emails or phone calls, while the outstanding is piling on with the bank.