I have not read the arabic Qur'an yet, i have still to learn arabic, but i dont know about the likeness of a man put over another who became the substitute for Jesus(Pbuh) the Ayat relating to this is Surah 4 ayat 157, ill provide two translations:
Pickthall:
004.157 And because of their saying: We slew the Messiah, Jesus son of Mary, Allah's messenger - they slew him not nor crucified him, but it appeared so unto them; and lo! those who disagree concerning it are in doubt thereof; they have no knowledge thereof save pursuit of a conjecture; they slew him not for certain.
Dr.Al-Hilali and Dr. Kahn:
Surah of the Woman ayat 157
"And because of their saying (in boast), "We killed the Messiah 'Iesa (Jesus), son of maryam (mary), the Messenger of Allah," - but they killed him not, nor crucified him, but the resemblance of 'Iesa (jesus) was put over another man (and they killed that man), and those who differ therein are full of doubts. they have no (certain) knowledge, they follow nothing of conjecture. For Surely; they killed him not [i.e. 'Iesa (Jesus), son of Maryam (Mary)]"
can you explain what you mean about disappointment?
Asalamu alaykum wa rahmatullahi wa barakatu