Consumer Redressal

Sir, I had given my santro car for servicing at barrackpur automobiles (authorised hyundai servicing centre) on 14/07/15.They had promised me to deliver it at home by evening.But there was some complaint in the compressor of AC they said by next day morning they will give.I asked him how much it will c0st.there was a vague answer like let it be over then we will tell you.the next day I had rang up at 11am ,they said the repair is still on and i asked what is the estimate.they never gave me a reply. At 3pm the receptionist rang me up and said mam You have to pay 16000/- for your car.I got a shock and asked how ?she said it comes that much in paid service.My car is 2008 model and till now I have not spend so much money for servicing.There were no such big damages also. They threatened me that they will not deliver the car at my home and said by next next day between 10am to 11am u come and give the money and take the car ,otherwise we will dump your car in our workshop. Kindly help