As for repeating one verse multiple times in the prayer is not authentically established from the Prophet (ﷺ) in obligatory prayers or voluntary prayers.
Ruling on repeating a Surah in the Salah
As for repeating one surah multiple times in one unit of prayer is not authentically established from the Prophet (ﷺ), nor from anyone from amongst the companions.
Making the first unit of prayer longer then the second:
Generally, the Sunnah is to make the first unit of prayer longer then the second, if one does the opposite to this then it is allowed for it was proven that the Prophet (ﷺ) also done it.
Those Who Are Unable to Recite Surah Fatihah:
If a person is unable to recite Surah al-Fatihah at all or is unable to learn it, or he has just become Muslim and the time for prayer has come and there is not enough time for him to learn it, then he is to act upon the following hadeeth:
Narrated by Abdullah ibn Abi Awfa: A man came to the Prophet and said: I cannot memorize anything from the Qur'an: so teach me something which is sufficient for me. He said: Say,
سُبْحَانَ اللَّهِ وَالْحَمْدُ لِلَّهِ وَلاَ إِلَهَ إِلاَّ اللَّهُ وَاللَّهُ أَكْبَرُ وَلاَ حَوْلَ وَلاَ قُوَّةَ إِلاَّ بِاللَّهِ
Say Glory be to Allah, and praise be to Allah, and there is no god but Allah, and Allah is most great, and there is no might and no strength but in Allah.
Hasan: Recorded in Sunan Abu Dawud (no. 832). al-Haafiz Ibn Hajar indicated that it is Hasan in al-Talkhees al-Habeer, 1/236).
All praise is due to Allah I pray Allah Azawajal bless the Prophet Sallah Llah Alei Wasalam and the companion and let's die on the path of Qur'an and Sunnah.