One guy didn't giving my hard earned money

In the event that you lend a person a sum of money and prevent this person from paying and you have proof of his borrowing from you, you can go to the court and request implementation directly as the bond is a judgment that can be implemented, but you should pay attention to the text of Article (260) in non-commercial articles
Article (260)
In non-commercial articles, if the value of the disposal exceeds 5000 QR, or if the value is not specified, its existence may not be proven or extinguished except by writing, unless there is an agreement or provision otherwise. An obligation is assessed as its value at the time of disposal. Evidence of witnesses may be proved if the increase in the obligation to five thousand riyals comes only from the annexation of the attachments to the original.
If the case involves multiple requests arising from multiple sources, the evidence of witnesses may be substantiated in any application not exceeding five thousand riyals, even if these claims in aggregate exceed that value, even if they originate between the opponents themselves or acts of one nature. The amount of the original obligation is the cost of the obligation.
Article 261
It is not permissible to prove the testimony of witnesses even if the value does not exceed five thousand riyals:
(A) In contravention of or in excess of what is included in a written evidence.
(B) if the rest is required or is part of a right that can not be proved except by writing.
(C) If one of the litigants in the case has requested more than five thousand riyals and amended his application to no more than this value.
Article 262
Notwithstanding the provisions of the preceding article, evidence may be proved in excess of five thousand riyals in the following cases:
1- If there is a proven principle in writing. Any writing issued by the adversary would make the alleged conduct probable is a proven principle of writing.
2. If there is a material or literary impediment preventing the obtaining of written evidence.
3- If the creditor loses its written bond for a foreign reason for which he has no right.
*** Therefore, if you are unable to prove, you can request the legal oath to be taken before the court as it is the decision to end the dispute