Consumer Redressal

Dear Sir, I have booked my Car Hyundai i10 (WB 08 4772) from Kolkata to Bhopal with Agarwal Shifting Solutions (GSTIN : 07AJXPA7686E1ZP)and had got a quotation of Rs 10350. When I spoke with the sales person that I had 5 cartoons with my kitchen utensils he said you pay Rs 12000 in total and we would shift your belongings. Hence I called them to my home and my wife handed over my car with the materials to them on 09.08.20. As told by them I had made them a payment of Rs 6000/- on 09.08.20. But then I was waiting for them to raise my invoice. They gave me the invoice on 13.08.20 on which the total amount was Rs 39,545.00. I then called them up and said to return back my car with its belongings as well as return back the Rs 6000 that was paid to them as advance as by then my car was still in the Dankuni godown and has not moved to Bhopal. Then again I had a word with a guy who promised me the total amount will be Rs 14500 including 18% GST and then I told him to share with me the revised invoice. The same discussion happened on 15th of August. But till now no revised invoice has come to me. I had been calling them regularly but getting such lame excuses that I am loosing my control. I need my car and I will not pay them such exorbitant amount. What to do from here kindly suggest.