Wei Jia Ban Mian Fish Soup is located inside the same coffee shop as Wan Jia Xiao Guan Zi at Blk 443 Clementi Ave 3 behind Clementi Mall. In case you are wondering, no, the two stalls are unrelated.
The stall offer variations of handmade noodle such as ban mian, u mian, mee hoon kway, koka noodle, ee-mee, bee hoon/mee sua, tom yum noodle, dumpling soup, dumpling noodle dry/soup, qq noodle, chicken/pork cutlet noodle, kimchi noodle, steamed dumpling and fried dumpling.
Strangely, there is no sign of fish soup on the menu. Perhaps they used to serve it but not anymore? Or maybe it is a off-the-menu item which you have to ask for?
I do not have the answer.