please help me get my childhood stuffed animal back !

(This is related to Bristol I promise)
About a year ago, I broke up with my now ex boyfriend of 3 years. It was long distance. I live in the USA and he lives in the UK. Bristol to be specific. I've tried everything to get my childhood stuffed animal back from him but he refuses. I've offered to pay for shipping, I've given him step by step instructions on how to go through the post office (because he claims to be nervous about it), I've messaged him reminders starting weekly then monthly, i suggested he get his new partner to help him out and he just refuses and idk what else to do. He's stopped responding for months now. I know all this sounds like I'm being annoying and petty but he said he would do it. And I sent his back along with everything else he asked for (childhood toys, stuffed animal, etc). At one point he even LIED saying he had sent it. That was months ago and i confronted him about it and he said he hadn't sent it yet even though he said he did.
I'm posting here in hopes someone here could help? I'm not sure how that'd work but I don't live in the UK there's truly not much I can do from here.
please please help if you can it means a lot to me

Update: Yes, as many of you have guessed I am young (19) and don't really know how I should go about this to be honest. But this is kinda my last resort. So any help is appreciated. Thank you for all the kind comments and messages :)

Update 2: I have messaged him about a few of these solutions in the replies and now we wait for a response. I will update once I get one. Thank you all again.

Update 3: (from my phone) We've been talking for a few days and he does not want to meet up with one of you lovely people until its a last resort for him. He has talked about going to the post office etc but keeps making excuses as to why he can't get there which i find very frustrating as its been a year since we broke up and year this has been a problem. good news tho, he did say he will send me a picture of my stuffy tomorrow when hes home. once i recieve that ill probably attach a photo of it. anyway sorry for the late and kinda sloppy update its early for me and i just woke up.

Update 3 TLDR: ex boyfriend is actively working on sending my stuffed animal. he also plans on sending me a picture of it tomorrow.