Jeremiah 15: Jeremiah is not happy with the Lord and prays about it.

 In Jeremiah 15 we read:

1  Then the Lord said to me, “Even if Moses and Samuel were to stand before Me, My [a]heart would not be [b]with this people. Send them away from My presence and have them go!

The Lord called Jeremiah to call His people to repent or to face doom; however, now, the Lord is so angry that He prophecies about Judah:

8 Their widows will be more numerous before Me
Than the sand of the seas;
I will bring against them, against the mother of a young man,
A destroyer at noon;
I will suddenly bring down on her
Shock and horror.
9 She who gave birth to seven sons withers away;
[d]Her breathing is labored.
Her sun has set while it was still day;
She has been shamed and humiliated.
So I will turn over their survivors to the sword
Before their enemies,” declares the Lord.

Jeremiah prays to the Lord:

5 You know, Lord;
Remember me, take notice of me,
And take vengeance for me on my persecutors.
Do not, in view of Your patience, take me away;
Know that for Your sake I endure reproach.
16 Your words were found and I ate them,
And Your words became a joy to me and the delight of my heart;
For I have been called by Your name,
Lord God of armies.
17 I did not sit in a circle of revelers and celebrate.
Because of Your hand upon me I sat alone,
For You filled me with indignation.
18 Why has my pain been endless
And my wound incurable, refusing to be healed?
Will You indeed be to me like a deceptive stream
With water that is unreliable?

Although Jeremiah delighted in the Lord in the past, now, he is wounded and he sees the Lord as an unreliable stream of water.
The Lord responds:

19 Therefore, this is what the Lord says:
“If you return, then I will restore you—
You will stand before Me;
And if you extract the precious from the worthless,
You will become [e]My spokesman.
They, for their part, may turn to you,
But as for you, you are not to turn to them.
20 Then I will make you to this people
A fortified wall of bronze;
And though they fight against you,
They will not prevail over you;
For I am with you to save you
And rescue you,” declares the Lord.
21 “So I will rescue you from the hand of the wicked,
And I will redeem you from the [f]grasp of the violent.”

The Lord calls Jeremiah to repent (return v19) so that he becomes His spokesman.