Seller not giving document (temporary registration certificate)

sir, My name is . i bought a car i20active from Hyundai gs road guwahati showroom on 3march 2017.. from the date of purchasing the car i dont get the temporary registration certificate yet.. from this issues i'm suffering a lots of problems through out.. bank call me to submit registration other wise the apply the charge of 5000/ rupees per month.. Sir i'm a defense person and facing many problems form this.. I try many times to the showroom for this issues and i talk many times The MD  and also salesman  but every time the gives me excuses only.. Sir please suggest me how can i get TRC soon...