Resignation after a year of completion.

Also, my employer has recently deducted 100 BD from our salary due to the market situation in Bahrain (that's what he said). I am not quite sure if that is possible since our contract states our full Salary without any conditions or whatsoever relating to any situation that allows them to deduct our salary.

How do I calculate my EOSB then? Is it from the recent salary or the salary stated in my contract?

End of service as per contract salary.

You don't have to pay anything. I have commented on this questions hundreds of times. Search the forum vs. Asking the same questions again.

Noted. I just want to confirm, after a year of completion, they refuse to give me my paid leave salary they will only give me my basic salary 50% and that's it.

Is there anyway i can show them in which Bahrain law it is stated that i am entitled to receive my paid leave after a year of completion.

You are entitled to get paid for your "earned' annual leave if you have not taken it.  On top of that, you get indemnity and any unpaid salary.  That is labor law.   I am not sure which paid salary you are referring to but it seems that you are confusing terms.   In any case, if there is a dispute, you need to approach Ministry of labor.