You have not told us whether this was within Poland or between two countries. Presuming the latter, it is almost certainly covered by the Montreal Convention.

That Convention does not provide for compensation, but rather provides for repair (or replacement) of the damaged bag as well as reimbursement for necessities which you had to purchase while your items were missing. The maximum total for both is approximately EUR 1,150, but it is important to remember that "fair market value" does not mean replacement value.

Air carriers are also permitted to impose reasonable reporting deadlines. Thus, if the bag arrived damaged, make certain that you follow LO's procedures for reporting.