That cannot be. There must be a way for it to accept these unicode characters especially if they work from their own software.#19 My customer doesn't accept that. I just have to find a different provider, that's all. I have found some, but at higher rates, although still better than eg. Skype.
Try writing to them.
Try searching in swedish - of if you are German in google.de.
I doubt very much that it simply does not work.