I Am A Victim Of Fraud By A Noida Based Interior Design Company

Hello faizan sir please help me I am victim of fraud. An interior design company based in noida quote me less amount for interior work, quotation was not signed by both of us, That was in my budget.. I gave them the payment of 4 lakh by cheque and 3 lakh by cash before lockdown( I did not get the receipt but the employee of that company can tell that they have taken the cash money because he was also involved in that project and now he is not the part of company but he can help me for the humanity). Now they have changed their company name and saying that the previous sales man made a mistake in quotation and this work is not possible in this budget.. You must increase the amount.. Now the project is not in my budget, and they are not returning my money.. What should I do.. Plz plzz plzz help me, I have no one to guide. They have done the work only 50 thousands approx now they are demanding more money, what is the guarantee whether they will do the work after taking more money