Is there a saying for NEVER SAY NEVER instead 'pa janm di jame'?

Try:

Jamè di jamè → never say never

or this expression:
Toutotan tèt ou pa koupe, ou pa ka di w p'ap mete chapo.
As long as you still have your head, you can't say that you won't wear a hat.

Haitian Creole ↔ English Reference, Look up Haitian Creole and English Words