Builder Cheating on Flat Specifications and Allotment

A 50x30 sqft flat was allotted to me in a new building project of Shri Om Builders in Delhi. The initial agreement had a 12th floor but the actual building has only 8 floors. On top of that, the flat size is 45x28 sqft which is less than what was agreed upon. There is a big tree nearby, making the east-facing flat dark during the day. Now, the builder is saying that this is a feature of the flat and I'm accepting it by taking possession. What's my remedy under the Transfer of Property Act and Consumer Protection Act? Can I cancel the allotment and get back my advance?