trthskr, your username suggests you're seeking 'truth'.
In your JW 'truth', Babylon's king was 'called to account' in 539 BCE, and then two years later, a period of 70 years of Jewish exile ended. Sounds simple enough...
But what does the Bible actually say? ...
Read Jeremiah 25:8-11. Who does it say would serve Babylon for 70 years?
Read Jeremiah 25:12. What order of events does it give?
In your New World Translation, look at the cross-reference for Jeremiah 25:12, immediately following "I shall call to account against the king of Babylon and against that nation". It points to Daniel 5:26, 30.
Read Daniel 5:25-31. When was Babylon's king called to account?
(Hint: Daniel's Prophecy, page 51: "Daniel was present on the night of October 5/6, 539 B.C.E., when the Medo-Persian army took seemingly impregnable Babylon and executed King Belshazzar. With the death of Belshazzar, the golden head of the dream image—the Babylonian Empire—ceased to exist. ... Medo-Persia replaced the Babylonian Empire as dominant world power in 539 B.C.E.)
If the point has not struck home yet, read Jeremiah 25:12. What order of events does it give?
Unable at this point to avoid the simple logic, the JW mind at this point sometimes defers to more ambiguous scriptures, typically ignoring the context of Jeremiah 29:10 or distorting the application of 2 Chronicles 36:21. But to be valid, any interpretation of those scriptures must be consistent with the plain order of events given in Jeremiah 25:12.