Poor customer service, no feedback and unable to deliver

A package was picked up on 3 Jan 2023, and on 9 Jan 2023 still not delivered. The tracking info said it was en route, then back at the sorting facility, then en route again, and now it says it is unable to effect delivery. I have tried their "chat" function (there is no other contact details available on their website) for 3 days, but have received NO response . I have googled and found a customer care number on a third party page. The lady that answered is helpfull, but also struggling to get internal confirmation.