Bank revealed account details

Who is the Third Person? Law enforcing Agencies, Income Tax authorities can obtain bank details with proper authorisation and banks are legally bound to give the same. If it's others, Bank is at fault but onus of proof is on you to prove that bank did not keep your account details secret and deliberately handed over to thers.

First, issue a notice under CP Act and seek all documents basing on which account details were provided to third parties.  Then if you find violations make a complaint before District Consumer Forum for deficiency of services as maintaining the secrecy of customer's transactions is a foremost legal obligation of Banker from times immemorial 

The main exemptions to this obligation are 1.Providing that information to a fellow banekr 2. In Bank's own interest 3.As per directions of law enforcement authorities including Court, Police, income tax authorities etc.