As per section 2(1)(c) of Consumer Protection Act 1986, "complaint" means any allegation in writing made by a complain­ant that a trader or service provider has charged for the goods or service a price in excess of the price 

(a) fixed by or under any law for the time being in force

(b) displayed on the goods or any package containing such goods 

(c) displayed on the price list exhibited by him

(d) agreed between the parties;