Belief at the Time of Punishment did not help except with the People of Yunus
Allah said;
فَلَوْلَا كَانَتْ قَرْيَةٌ امَنَتْ فَنَفَعَهَا إِيمَانُهَا
Was there any town (community) that believed (after seeing the punishment), and its faith (at that moment) saved it (from the punishment)--
Allah asked, `did any town from the previous nations, believe in its entirety when they received the Messengers All of the Messengers that We sent before you, O Muhammad, were denied by their people or the majority of their people.'
Allah said,
يحَسْرَةً عَلَى الْعِبَادِ مَا يَأْتِيهِمْ مِّن رَّسُولٍ إِلاَّ كَانُواْ بِهِ يَسْتَهْزِءُونَ
Alas for mankind! There never came a Messenger to them but they used to mock at him. (36;30)
كَذَلِكَ مَأ أَتَى الَّذِينَ مِن قَبْلِهِمْ مِّن رَّسُولٍ إِلاَّ قَالُواْ سَـحِرٌ أَوْ مَجْنُونٌ
Likewise, no Messenger came to those before them but they said;"A sorcerer or a madman!" (51;52)
and,
وَكَذَلِكَ مَأ أَرْسَلْنَا مِن قَبْلِكَ فِى قَرْيَةٍ مِّن نَّذِيرٍ إِلاَّ قَالَ مُتْرَفُوهَأ إِنَّا وَجَدْنَأ ءَابَأءَنَا عَلَى أُمَّةٍ وَإِنَّا عَلَى ءَاثَـرِهِم مُّقْتَدُونَ
And similarly, We sent not a warner before you to any town (people) but the luxurious ones among them said;"We found our fathers following a certain way and religion, and we will indeed follow their footsteps." (43;23)
As found in the authentic Hadith,
عُرِضَ عَلَيَّ الاَْنْبِيَاءُ فَجَعَلَ النَّبِيُّ يَمُرُّ وَمَعَهُ الْفِيَامُ مِنَ النَّاسِ وَالنَّبِيُّ يَمُرُّ مَعَهُ الرَّجُلُ وَالنَّبِيُّ مَعَهُ الرَّجُلَنِ وَالنَّبِيُّ لَيْسَ مَعَهُ أَحَد
The Prophets were displayed before me. There was a Prophet who passed with a group of people, and a Prophet who passed with only one man, a Prophet with two men, and a Prophet with no one.
Then he mentioned the multitude of followers that Musa had, peace be upon him, then that he saw his nation of people filling from the west to the east.
The point is that between Musa and Yunus, there was no nation, in its entirety, that believed except the people of Yunus, the people of Naynawa (Nineveh). And they only believed because they feared that the torment from which their Messenger warned them, might strike them. They actually witnessed its signs. So they cried to Allah and asked for help. They engaged in humility in invoking Him. They brought their children and cattle and asked Allah to lift the torment from which their Prophet had warned them. As a result, Allah sent His mercy and removed the scourge from them and gave them respite.
Allah said;
إِلاَّ قَوْمَ يُونُسَ لَمَّأ امَنُواْ كَشَفْنَا عَنْهُمْ عَذَابَ الخِزْيِ فِي الْحَيَاةَ الدُّنْيَا وَمَتَّعْنَاهُمْ إِلَى حِينٍ
Except the people of Yunus; when they believed, We removed from them the torment of disgrace in the life of the world, and permitted them to enjoy for a while.
In interpreting this Ayah, Qatadah said;
"No town has denied the truth and then believed when they saw the scourge, and then their belief benefited them, with the exception of the people of Yunus. When they lost their Prophet and they thought that the scourge was close upon them, Allah sent through their hearts the desire to repent. So they wore woolen fabrics and they separated each animal from its offspring. They then cried out to Allah for forty nights. When Allah saw the truth in their hearts and that they were sincere in their repentance and regrets, He removed the scourge from them."
Qatadah said;
"It was mentioned that the people of Yunus were in Naynawa, the land of Mosul." This was also reported from Ibn Mas`ud, Mujahid, Sa`id bin Jubayr and others from the Salaf