Amrapali Group — Decreas in price o[censored]nder construction falt rate

Address:

Gautam Buddh Nagar, Uttar Pradesh

I booked Amrapali centurion park low rise 1675 sq ft in last year for 70l and now they are selling same size in same avenue for 58 L only . pls advise me what should I do ? Can a builder decrease flat rates for under construction property ? Should I go legal as they are not giving me any credit for the reduced rates and asking me to pay full 70 lacs...