First, is your company covered under LL #14?  If its a private comapny, it probably does but if its a government co, a or a Qatar Gas co (among others), it is not.
Second, the end of service gratuity really applies after 2005-its a bit of a contentious issued but, you couldn't go back to 2000 and expect 24 weeks of ESG.

If it does apply, aak is right, this part of the contract is in direct contradiction to the ll#14 and doesn't apply.  Good luck!