

I have a first middle and last name. My last name has a space in it and no matter what I do, shortening my name, using initials etc., they just will not accept it.
In the first instance, you can only write up to 8 characters anyway and both my first name and last night have seven letters each in it. In the kana part, my name on my MyNumber Card doesn't have kana and they keep asking me to write it as it's written on my card, which I'm trying to, but again, all three of my names combined exceed the 18 character limit meaning that I'm having trouble there as well.
I'm not even sure who to contact. I tried their chat feature and I couldn't even get through to that because god knows!!
People with long names. Help me!!