To update. It's now been 10 weeks and they still can't say when my bike will be delivered.
They simply say to email at the end of the week.
When I then email on Fiday, they ignore the email on Monday and tell me to wait again.

To really irritate me, they've been spamming me twice a week since I ordered the bike.
The latest spam is to announce a UK delivery centre that will reduce waiting time from 8 weeks to 15 days.
I had to laugh at getting spammed about quick delivery while awaiting delivery. :S

A bit of googling shows other people having similar problems. One person say they have waited 12 weeks.
https://uk.trustpilot.com/review/radpowerbikes.eu

Hi,

I ordered a RAD wagon 4 cargo bike and accessories on 18th May and was told it will take 5-8 weeks for a UK delivery from the .eu website.
I received the accessories within 2-3 weeks but it's been 9 weeks and I still don't have a bike.
Frustratingly it had been for a birthday gift and I missed the date.

Has anyone else received a bike to the UK? Or from the .EU site? Lately.

getting worried as I spent ?2000+ and if I order a different bike I'll have to do something with all the accessories.

Update 2022-08-18: Bike and all parts arrived ~3 weeks late. The bike is awesome!! 

Thanks,
Ryan