1)
Why does it say "Ki Hayu b'Tzo'an Sarav"?
1.
Rashi: Melech Yisrael's officers were on a mission to Melech Mitzrayim.
2.
Radak: Yehudah's officers were in Tzo'an (of Egypt).
3.
Malbim: Melech Mitzrayim's officers, that he sent to help you, remained in Tzo'an (Egypt's capitol). I.e. they did not go to help you at all.
2)
Why does it say "u'Mal'achav Hanes Yagi'u"?
1.
Malbim: However, the messengers that Melech Mitzrayim sent to collect the gift and tax that you promised to him, they arrive until Tachpanches, to where the gift is sent, to receive it.
