get back vs pay back

get back and pay back both are verbs.

Word	Noun	Adjective	Verb	Adverb
get back	No	No	Yes	No
pay back	No	No	Yes	No

As verbs, pay back is a hyponym of get back; that is, pay back is a word with a more specific, narrower meaning than get back:

Other hyponyms of get back include fix, get, pay off.

get back (verb)	pay back (verb)
take revenge or even out a score	take vengeance on or get even
recover something or somebody that appeared to be lost	act or give recompense in recognition of someone's behavior or actions
get one's revenge for a wrong or an injury