False Advertising

Why do we in Singapore put up with it, and is there anything we can do / anyone we can report it to? I really don't see why businesses that do it are allowed to get away with it. And even if there is no official organisation we can turn to, I believe that the more people refuse to accept such 'behaviour', fewer businesses will resort to it / think they can get away with it.

Case in point:
I saw an ad printed out on a piece of A4 sized paper and pasted on the glass wall of the establishment stating:

"Good Friday 2008
20% discount
for fish therapy only
From 21st March - 23 March 2008"

other information included the establishment's information.

I happily went in to inquire about their fish therapy services and prices, with the intention of trying it out. Just before I started the treatment, I sought confirmation about the 20% discount and was informed that it was for packages only. Now, nowhere on the advertisement was it mentioned that the discount was for packages only, not was it indicated that terms and conditions apply. When I pointed that out, I was told, "This is to capture the interest of potential customers." To which I responded that they lost this potential customer for good and promptly walked out.