Help!! Parcel sent to previous address

[Aliblanco]

First of all, I’m fully aware the whole situation is completely my fault. I recently bought something on a Facebook page and paid using PayPal, stupidly didn’t check the address and it defaulted to an address I haven’t lived at for 5 years. Only just realised my mistake when I chased the seller, she sent me the postage receipt with my old postcode and house number. Royal Mail tracking show it as delivered and signed for yesterday, the signature is initials but the signed for name is my surname.
I googled the address and it came up with a company based at the address, messaged them via their Facebook page and they are actually next door, it’s 1 old property divided into 2, so 10 and 10a. They said next door is currently unoccupied, they’ve kindly looked outside to see if it’s been left in a safe place but couldn’t find anything. The parcel is small enough that it could fit through a letterbox so I can only assume the postman has signed for it and posted it. The house is 150 miles away so I can’t just pop round, also the owners live miles away. Any ideas what I can do next?

Have you contact the owner of the property that's empty ? Ask them to have a look for you

Haven’t got a clue how I’d get hold of them, from memory they live about 200 miles away from the property.

Look on Rightmove and see if it's got a property listing up, then you could contact the agent.

Or if you really want, you could do a Land Registry search to find the owner's details but it'll cost you about £5 to do so. Even if the owners live far away, they might have a friend or agent nearby who has a spare key.

The lady from next door said they aren’t using an agent, it was advertised to rent on Facebook marketplace, I can’t see it on there though. I’m going to give the agent we let the property with a call on Thursday to see if they could contact the owner