says who?
US /ˈsɛz huː/
UK /ˈsɛz huː/

1.
siapa cakap?, kata siapa?
used to express doubt or disagreement with a statement, implying that the source of the information is questionable or lacks authority
:
•
You can't do that. Says who?
Awak tak boleh buat macam tu. Siapa cakap?
•
They told me I'm not allowed to enter. Says who?
Mereka beritahu saya tidak dibenarkan masuk. Siapa cakap?