Fraud by home renovation Civil contractor

Dear Sir, I have given contract for Home renovation of 1BHK flat to a civil contractor. Work Includes -Floor Tiles replacement , Bath room renovation including plumbing tiling,POP concealed Electrical wiring, Kitchen Trolley and Kitchen ota replacement.Painting,and Door replacements This was agreed verbally and there is no written commitment registered by us as he denied to do so. The work was started on 8th April 17, since then i have paid him more than 4.9L till last month he has not even given receipts of the same. but i have whats app records of payed amount. now it is more than month he is not coming to complete the work and asking more money for exta work done -extra work includes 10x10 wall demolition(10000), diverter tap fitting in bathroom(9000), and extra electrical points(850 per points)He is asking exorbitant high amount for this. i have agreed to pay as per market rate but he is not accepting that too. now nothing is completed and i am doing work by my own and spent around Rs.50000.over 5Lakhs. since last 3.5 months i am staying away and he don't bother and says it takes time to do this kind of civil work. i am feeling help less.still there is work pending around Rs.1lakh which i need to get it done from him, can somebody help.