I had my account frozen by FJ, and I didn't notice that for the longest time because I hadn't used them for almost a year. But then a dream dress popped up and I came back and wanted to place a bid and noticed I couldn't add balance to my account anymore, there was some message poppig up that I got blocked. I was like wtf why am I blocked and emailed them.
Their response was that some months before I placed an order which I never paid shipping for so they banned my account. It turned out that it was an item on my watchlist which I placed a sniper bid for but I decided I didn't want it anymore, so I deleted the listing. But apparently you can't delete listings that already have sniper bids on (why does this option then exist in the first place?), their automatic system will still place the bid so that is what it did. There was nothing in my buying history so there is no way I could have known that this happened. I also didn't pay attention to my email account since it's 99% spam so it completely slipped through my knowledge. Of course they didn't accept my apology and request to unblock my account. I used to be Shogun rank, so they should know that I'm not an unreliable person. I also still have points in my account which I can't use. But they don't care. It's no surprise that they randomly block your account for stuff you probably don't even know had happened.
When I still could use them they once ordered the wrong item and tried to brush it off as my own mistake even though I could prove that I gave them the right link and order information. They refused to exchange the item even when I offered to pay for the shipping costs. On top of that the item they accidentally ordered was several 1000 yen cheaper but they didn't even offer to compensate me for the amount that I paid too much for it since it was all my mistake according to them.
I can only advice to everyone to stay away from FJ, especially if you're hunting for your dream dress.