criminal civil or consumer forum

Issue legal notice to dealer and ask him to remove defects exists in car if he does not remove or ignore then file complaint  before District Consumer Commission .

Besides consumer fora a police complaint / FIR of cheating and fraud and a civil suit for permanent and mandatory injunction would be maintainable.

consumer court can be expected to give effective remedy.

however criminal case of cheating can be filed by giving application to the ilawa magistrate if police has abstained from registering FIR.

You have option to approach the consumer forum as well civil and criminal actions.

Perhaps, serving the legal notice itself may resolve the issue.

You can approach the issue through criminal law for the offences of cheating, breach of trust etc. 

You can approach consumer commission for deficiency in service, unfair trade practice and for recovery of the amount paid.

You can discuss with a local advocate and proceed as suggested