The three-story facility having 181 trading stalls was given to traders from 2010.
President of their association U.H. Gayan says the Rs. 1,750 per stall rental has been raised by 1,400 per cent for stalls in the ground floor and by between 1,000 pc and 1,100 pc for stalls in the first floor.
Unable to pay the high rentals, several traders have already closed their businesses.
The association urges the urban council to bring down the rentals recommended by the valuation department.
When contacted, UC chairman Sasanka Sampath Sanjeewa said the valuation department evaluated and made recommendations seven years after the supermarket complex was handed over to them.
According to him, the new rates are not high.