Cancellation of booking with deduction from allotment money

Hi I have booked a under construction flat on Dec 2014 by paying Rs 2 lacs as EOI money - expression of interest through a marketing agency who was selling those project of a reputed builder at Kolkata.( total property cost is 71 lacs) I was instructed to pay 20% of property cost with in 60 days of allotment letter so that agreement can be executed. Received allotment letter date 9 th Feb 2015. Have applied for home lone from my bank and they wanted property documents for approving the project Builder could not provide sanctioned plan as they reapplied that to giver dept. and waiting for sanction due to some design change . I refused to pay any money till I get the sanctioned plan as my banker insisted that 22nd August 2015 builder could provide the same . My banker took 2 months time to approve the project . My builder was insisting me to pay 20% of owner contribution which I didn't pay as I had agreement with my banker that all payment will be done on prorated basis. During this time builder started saying the project delivery time delayed to end 2018 / early 2019 but during application Marketing company said it would get over mid 2017 max ( no written communication ) I changed my mind and communicated to marketing aganecy and told them to find ready property for me on whichbtheyvare working as well I just a got a allotment cancellation letter with a clause of deduction of 1.81 lacs ( in account of interest for delayed payment) and letter says allotment stands cancelled with immediate effect and builder has now every right to sell the said property to any new buyer My question how builder is cancelling the allotment and also deducting 1.81 lacs from my 2 lacs initial payment. What should I do ? What is my legal stand Please help