selling a watch at negative experience

It's not patriotic for me to tell this, but they don't know how to make an Identity check request in adequate polite manner.

I am not a watch reseller, I just like watches, sometimes buy or sell one,
spend a lot of time watching different pieces on the web. it relaxes me  :)

2 months ago I was selling one genevan watch, found a buyer in my city (the orthodox church pastor) and forgot about this... but.....

once apon I time when I came to the to look for nice watches, may be something will appear interesting for me.....

it prohibited me even to read the site (!) and forums (!) everything was blocked for me.
the message just told
you are banned forever
reason: not specified.

after 2 days after writing to their support they told me
that I have a suspicious ip addresses
and a long letter saying that I'm totally suspicious. and if I want... I can write something to admin... and he may be will change a decision... etc etc etc.

I understand why it's needed to verify indentities sometimes, but some sites don't know how to do it accurate, without confusing people, in polite manner.