Re UK import charges, it depends upon how the item is described by the sender.

Firstly, no documentation should be included with the package, such as invoices etc, because they show its a purchase.
Secondly, if anywhere on the description the words 'human hair' is used, then the package has to be held & investigated as a potential bio-hazard.

Thirdly, there can be an issue over 'value'.
If you have the item sent with insurance for loss or damage, the sender has to confirm its value on the package.
Customs may then use that value to assess its worth and charge you VAT (@ 20%) on top.
This can apply to items even sent as 'gifts'.

The best description for import duty avoidance is:
Repaired Synthetic Head Wear or Head Gear.

Sometimes you can get called by DHL (or other couriers) asking you to confirm what it actually is. You can say its just a specialist thing you need to wear on your head for..sport..drama..medical reasons..whatever and it will be ok.
I've even said its a special type of head phone!
Its important to stress its something thats been sent back to you having been repaired as this is not considered a purchase.

I believe I'm right in saying couriers levy their own handling charges to clear something through customs that is liable for import tax, so if you don't say the right things, you get stung for extra charges twice.
This means the couriers have an interest in trying to get you to pay import tax too as their handling charges can be up to £20.

I have disputed charges in the past and received a refund, but it takes ages.