@ MaskedMarvel: Welcome to Stridaforum, I’m sorry to hear you have trouble.
Here is your tyre dimension: https://www.stridaforum.com/t/strida-mini-tires/329/1]
Any tube with the dimension 14 x 1,5" should fit your mini.
Please ask your local bikeshop, if they don’t have such tubes you may write to Strida USA:
[url]http://www.strida.us/dealers.asp
Please post pics for specific problems!
Thanks!
@ Rapunzel: Fine to detect you are still here! 
No new riders reports because of ugly weather conditions, I guess? 
B. r.