Have received multiple calls from this number within the last few days. No one there, just hangs up a few seconds later. Have also been receiving a lot of insurance scam (have you been in an accident recently?) calls from Unknown numbers lately too... maybe related.

Suspected scam - requesting details about a vehicle accident within the last 12 months and then want you to provide the details - refer to Scamnet - https://www.scamnet.wa.gov.au/scamnet/Scam_types-Attempts_to_gain_your_personal_information-Phishing-Car_Crash_Compensation_Phone_Scam.htm

Probably another charity