Mantri Developers — not honouring their commitment

Address:

Bangalore, Karnataka

I had invested in mantri blossom in benguluru in 2015 under a buy back scheme provided by the builder. Under the buyback scheme i need toinvest 10% of the property cost and after 36 months mantri will refund back double of my equity investment in my property. I will take a loan from pnb housing finance, where the preemi on the loan will be paid by mantri for the 36 months. At end of 30 months i need to inform the builder of my intention to exercise the buy back which i did through my email to mantri on 15th september 2017 which i get a confirmation from mantri on 16th september 2017 that they acknowledge the mail and do the needful. I followed up with mantri on regular basis as to whether any formalities to be completed in regards to the buy back, they revert back on 17th october 2017 with a document which i need to sign. I sign the document and send it to mantri. I followup with mantri to confirm with them if any thing else is required, on 14th november they revert back stating nothing else is required.in april 2018 i followup with mantri to check the status of the refund of investment under buy back agreement, till today they have not refunded my investment. They have stopped paying the preemi on the loan which i am bearing. They are pushing me to keep the property which i have refused and they are delaying the refund of my money. Need your help to sort this out as the emi that i am paying is a burden to me. Please help.
I could not upload the agreement and email communication as it is not accepting in the upload