"La birra non l'ho più voluta."
A literal English translation requires a comma: "The beer, I didn't want it anymore". Italian allows to get rid of the comma and keep the sentence as it is, as broken as it may sound. The purpose is exactly the same as the English sentence, to focus the attention of the listener on "beer".
P.S. It's also a way to move the object before the subject unambiguously; but the reason to change the word order is the same, emphasis.
I didn't want any more beer: "Non ho voluto più birra" (but "Non ho voluto altra birra" is more common)
I didn't want beer anymore: "Non ho più voluto birra"
In the first case più refers to the object (più birra) and must be close to it; although it's rather uncommon in this negative form.