The expression “to get one’s come uppance” means: To receive the fate one has merited; to get what is coming to one in the way of chastisement or rebuke.
Though “come-uppance,” in the sense here used, is said to be dialectal English, we think it is American, perhaps a modification of English usage, however.
Our cousins spoke of one’s “come-uppings,” rather than “come-uppance,” and the latter has been our usage since the Civil War at least.
The phrase was in use long before his time, but William Dean Howells gave it the stamp of literary approval when, in Silas Lapham (1884), he wrote: “Rogers is a rascal. But I guess he’ll find he’s got his come-uppance.”