Mobile phone shop Mobile Air was asked by the Consumers Association of Singapore (Case) to sign a Voluntary Compliance Agreement (VCA) because of the large number of local complaints received.

Under this agreement, the shop will have to admit that it has engaged in unfair practices, agree to stop such practices and compensate the complainants, said Case executive director Seah Seng Choon.

The High Court has also granted a permanent injunction against electronics company Cyber Maestro. The Singapore Tourism Board (STB) had applied for the injunction because of the large number of tourist complaints.

An injunction means the company must not engage in any more unfair practices, or it will face the law under the Consumer Protection (Fair Trading) Act (CPFTA), said lawyer Chen Chee Yen.

Since March 2004, Case has taken up about 17 VCAs against businesses with unfair practices and five injunction proceedings against errant companies.

The management council of Sim Lim Square said on Monday that the problem of errant retailers persists despite its best efforts and cooperation with Case, STB and the police.

"Law enforcement officers can be sighted in Sim Lim Square almost every day. However, the errant retailers are completely undeterred as the authorities appear to lack 'teeth' to take them to task," it said in a press release.

Mr Chen said these agencies often require clear evidence before enforcement can take place.

He added that it is often a challenge for consumers to prove that the seller was intending to "trick" them.

"The evidence could come in the form of CCTV footage or recordings of conversations that could reveal a certain pattern of behaviour.

"But the customer is usually not in a good situation as the CCTV footage is in the hands of the shop owner."