To think my neighbours are CF's?

Are you concerned about them letting their dog bark again, or something else?

But I'd have done the same as you did.
If they take umpage and let the dog start barking again it'll back fire as, hopefully, the recording equipment will kick in and pick the sound up.

You've made quite a few posts about your neighbours now. At this point it's starting to feel a bit like you're trying to find reasons to dislike them.

It's entirely possible they didn't say that to the courier. I've had courier companies say to my neighbours have said I should take receipt of parcels, and also tell neighbours that I have asked that they take parcels for me, when nothing of the sort has ever been said.

YANBU to refuse the parcel.
YABU to assume the courier wasn't lying and to keep posting about these neighbours. You have valid reasons to be annoyed about them, but it's starting to feel a bit like a vendetta at this point and anything is a 'slight' against you.

The courier company probably either a) just has details on file from deliveries long before you had any dispute with them, b) just has 'leave with neighbour' without specifying your address and meaning any neighbour who happens to be available, or c) the courier just said that because he wanted to get rid of the parcel.

Either way, it really isn't an issue. You're not obliged to take in a parcel and you're making a big deal over nothing. The dog barking issue is currently being dealt with but you're already annoyed about the potential for it happening again even though there's nothing to say that it actually will.

I appreciate nuisance neighbours are awful - believe me, I've experienced them myself - but you aren't doing yourself any favours by obsessing over additional things that are non-issues.

If they are keeping the dog very quiet thats great

You've complained about the dog, surely the ultimate aim is they keep the dog quiet and now they are but that's annoying you? The courier wasn't necessarily told that, v he's just trying to get rid of the parcel.
Hopefully this is the start of better neighbourly relations.