Nintendo UK has started emailing customers to let them know that issues that arose with regards to the Build your amiibo Bundle has now been resolved and that items should now be going through as normal. Here’s what they had to say about the issue on the Nintendo UK Store.
Dear Nintendo fan
We apologise, we have experienced some technical issues with Build Your amiibo Bundle for New Nintendo 3DS, New Nintendo 3DS XL and Wii U over the last few days. These issues have now been resolved.
Nintendo Official UK Store