Bdi Green Park Chikani Bdi Group - Lift promised by builder but not installed and possession not given

Hello. I booked *BHK flat in BDI Green Park Chikani Alwar for ******/ which later on alloted by the company on *th floor in draw. Registry already done for raw flat as compnay has a tie up with HDFC Home loan. At the time of booking, the builder executives promised that there will be LIFT facility in the tower obviously because its *th floor. But now the executives are saying that there will be no lift facility in these flats. They mislead me giving fake promises at the time of booking and I am paying EMI for this flat since last * years and the loan is still due. I requested the executive that me and my husband are senior citizens having age more than ** years. I requested them verbally if they can allot a ground floor but they said its not their problem and not possible. They have not given me the flat possession and keys but still they are sending me monthly maintenance charges notice whis is around ***** and harrasing me. They even did not replied to case no.******* date **-**-** which I raised through NCH.