Under section 28 of the specific relief act specific performance of the contract cannot be enforced against a party in any of the following cases.
1. If the consideration to be received by him is so grossly inadequate with reference to the state of things existing at the date of the contract as to be either by itself or coupled with other circumstances evidence of fraud or of undue advantage taken by the plaintiff.
2. If his assent was obtained by the misrepresentation (whether willful for innocent) concealment circumvention or unfair practices of any party to whom performance would become due under the contract or by any promise of such party which has not been substantially fulfilled.

3. If his assent was given under the influence of mistake of fact misapprehension or surprise.