I sent five parcels using a UK parcel delivery service called parcelhero. The parcels were collected by parcelforce UK. Only 1 of the parcels was delivered, another was returned to sender, and three are still missing. The phone number of the parcel delivery service does not work, and chasing parcelforce UK is futile. The missing parcels contained valuable items such as a passport, notebooks etc.
Considering one of the missing parcels contained a passport, what kind of action can I take against the parcel delivery service?