Pending Interior work

My interior designer has taken advance of more than 90 percent for my flat interior work but have completed only 80 percent work and are not willing to complete balance work nor willing to return my money. He has delayed the whole interior work and almost double the time has passed than the time mentioned in the contract. The quality of work is also poor and not as promised by him. Fittings and material are of poor quality and he don't want to take any responsibility. His pending work includes sofa, sofa and bed Dinning table and chair, centre table, bed headboard and jali work along with light work,wall paper and miscellaneous fitting, light, glass, paint, laminate,marvel and basin work. At this point I am very much confused how I get these work completed. With such miscellaneous work pending, it is very difficult for us to get it done by any other interior. Now I want to understand what action we can take to get these work completed by my interior because request alone is not working on him and he think that apart from that we can't do anything against him and we are at his mercy to get things done from him since the contract does not include any clause of penalty though time and amount is mentioned as well as the detail of interior work given. Proof of payment along with his signature is also there. His behaviour is very unlikely and irresponsible. Kindly guide us. Thanks