Was this package treated as high priority mail (as requested)?
Was my package correctly handled as priority mail?
My package arrived very late. I paid extra money for it to be treated as priority mail. Was it handled as such?
「最優先便」＝ priority mail / high priority mail / highest priority mail
「荷物」＝ package / parcel
「取り扱う」＝ handle / treat
「この荷物は最優先便として正当な取り扱いをしましたか？」＝ Was this package treated as high priority mail (as requested)? / Was my package correctly handled as priority mail?
「荷物が遅れて到着しました。優先度の高い料金を支払っているので最優先されたのか」＝ My package arrived very late. I paid extra money for it to be treated as priority mail. Was it handled as such?
イギリス 
