What does an unapproved leave extention cost you?

Our admin didn't approve my application for a Xmas vacation leave due to fare cost issue, though it has been signed by our Dept head. Instead, he moved it earlier Nov. 27 to Dec. 12. A 15-day leave for an 8-month service is what they give and that includes flight time equivalent to 3 days for the round trip. He didnt give me other options.

I took it but thought of extending the leave to Dec. 26 (14 days) myself by directly contacting the airline to rebook my flight schedule. He won't approve any application for extension anyway so I really rebooked my flight.

I sent an email on Dec. 9 informing the leave extension but to my surprise, the admin replied and said my job will be terminated and he really did also. He was able to convince my boss to terminate me. However, they give me clearance because I was then appointed by a staff in other project, but in the same company under a different contract.

They sent me a Statement of Account which stated a receivable certain amount of money as my service benefit in a pro-rated basis. A month later the admin informed me that I will not be able to receive the amount for the reason that I made an AWOL.

Is there any way I can do to get the money? Is it legal for an employment contract with a foreign company in Saudi Arabia stating a 15-day leave for an 8-month length of service?