"I want the change."

Translation: Tôi muốn sự thay đổi.

[ElleninEdmonton]

In English, I want the change means I want my change in money back from a big bill. Change, as an abstract noun, is noncount, so we wouldn't say "the change". We might say that we want a change, when we want something in our lives to be different, not everything.

[TehVanarch]

Unless of course it's specifying a specific "change" that you and the other person know of, though normally it would be followed by some other words like: "I want the change (that you mentioned) to be realised".

[Huy_Ngo]

Yea.
FYI, change (the money given back from a big bill) is called tiền dư/thừa ("redundant/excessive money"), tiền thối (dialect, maybe, no idea why it is called so, but "thối" doesn't mean stinky here), tiền trả lại ("given-back money")

[Kieron657731]

'I want change'. With abstract uncountable nouns, we rarely use an article ('change can be both uncountable and countable but in this context it is uncountable). We do occasionally, but (like the previous poster said) in this instance 'change' and 'the change' have completely different meanings.