We've passed this to the team immediately this morning. Thanks for taking the time to report/PSA this and really sorry this happened to you.

Our Player Support team should be able to help you with this. You can get in touch about your lost items here and they'll conduct a thorough check to verify/validate the claim: https://support.runescape.com/hc/en-gb/articles/360000867937-Lost-Items-Claim