GIAS II is listed as soon to be discontinued:
https://bride-jp.com/en/seat/gias/
That means they aren't making any more. There may be dead stock, as justin said, so you just have to call/email around. We aren't doing that for you, you have to put some work in yourself.
hell, email LOT USA directly and ask. Worst they can tell you is they're out.
There's also all the usual japanese parts importers but that's going to be random