what can i do if my employer decrease my salary?

If your inquiry is related to the employer's refusal to pay the full salary, here is the following information::
If your inquiry is related to the employer's refusal to pay the worker's salary, here is the following information:
The employer’s refusal to pay the worker’s salary in full or any other financial rights, is a matter that gives the worker the right to file a complaint with the labor office to which the workplace belongs.
As the employer has no right to reduce the salary specified in the work contract
Here is the text of the Saudi Labor Law, related to your inquiry:
Article ninety:
1- The worker’s wages and every amount due to him shall be paid in the official currency of the country, and the wage shall be paid in the hours and place of work in accordance with the following provisions:
1/1- Daily workers are paid their wages at least once a week.
1/2- Workers with monthly wages are paid their wages once a month.
1/3 If the work is performed by piece, and requires a period of more than two weeks, the worker must receive a payment every week in proportion to the work he has completed, and the rest of the wage shall be paid in full during the week following the delivery of the work.
1/4- In other than the aforementioned, workers shall be paid their wages at least once a week.
2- Wages may be paid through approved banks in the Kingdom, if the worker agrees to that, provided that the due date does not exceed the dates specified above.