I used Parcel2Go when I had to send my Moots back for repair. Think I paid £75 to get it there. Moots sent it back with FedEx, at my expense (around £100 at the time with the exchange rate being good!). That was just a frame though.
If you’re sending it back as a warranty, make sure you say so on the Customs forms. I ended up saying it was a repair (didn’t mention warranty – as it wasn’t!) and had to pay £150 import charges and tax and that was AFTER they delivered it. Tried to say it was warranty work, even got a letter off Moots to say it was (even though it wasn’t) but still had to pay the thieving robbing HMC&R barstewards 🙁 (my fault though).