He studied in an institute by means of a trick; shouldhe work in the profession that he has learned?

I entered a professional institute which only requires a high school
certificate (secondary education). I have a diploma from the same
government foundation towhich this institute belongs, but they won\'t
accept you if you have anycertificate higher than the general high
school certificate. So I did not tell them that I have a diploma and I
gave them the high school certificate only. They accepted me and I
studied with them and learned a profession, but after that I regretted
itand repented and I graduated from this institute but I did not take
the certificate from them. Is it permissible for me to practice this
profession that I have learned with them, or is it haraam for me to
practice this profession because I learned it by means of a trick?.
Praise be to Allaah.
It is not permissible to use tricks in order to study in these
institutes and go against the conditions thatthey have set out,
because Allah says (interpretation of the meaning): "O you who
believe! Fulfil (your) obligations" [al-Maa'idah 5:1]. And the Prophet
(blessings and peace of Allah be upon him) said: "The Muslims are
bound bytheir conditions." Narrated by Abu Dawood (3594) and classed
as saheeh by al-Albaani in Saheeh Abi Dawood.
But there is nothing wrongwith you practising the profession that you
learned, even if you learned it through a trick or by impermissible
means. It is not one of the obligations of repentance that the
penitent should forget about the profession that he learned or give up
working in that field; rather he should ask Allah for forgiveness for
the wrong things he did and work in whatever permissible field he
wants.

And Allah knows best.