A lot of money changer. Work around for better rate.

The most competitive exchange rate is provided by Max Money in Sungei Wang Plaza

I used the money changer at the entrance on the left, ground floor near the monorail, it was good.

I use 2 and they're both on ground floor (street level). They're at the entrance where you see the monorail. There's a few chocolate shops right there next to both exchange places.