Offenses in stalls being coducted in tech parks

I work in a software company. My company is in a tech park constructed and managed by private construction company. This week they gave permission to a private organizer to have an promotion event in their tech park. So organizer had 5 cloth stalls in that event. because of the reputation of that constructor we are provoked to trust the vendors in that event. we purchased some items with refund guaranteed for returns in a single day. But when some of us went for return the goods next day it turned up a very bad incident with vendors. So we approached tech park management. Tech park management says that they will give permission in their tech park to anybody regardless of credibility and conduct. They say that they have never forced or encouraged anybody to buy goods in the stalls so they are not responsible for anything that happens there. This is really so bad. Law clearly says "owner is responsible for what happens in his own place". So I want to go for legal action on them. kindly give me your valuable suggestions. if everything is good I would like to hire the lawyer which comes with best approach.