I just placed the order through my account choosing USD wire for payment method...
I second this.
Finally, I understood what they meant after few goings in between.
1. You need to find out how much your credit is. For me, it turned out to be the sum of two invoices difference for S17e and T17e orders.
They told me the $ value of credit exactly once I said that I would like to receive credit for a new order. However, instead of giving me credit (which i expected), they first told me just how much it is.
2. Then, you put in an USD order (now it is only the wire visible), choose the wire method, click submit. This would generate the new order number and an automatic email.
3. Then, you should send another message to Bitmain rep saying to apply your credit to a specific order number (generated).
4. They would apply credit to it in a few hours, which is OK since wire orders have 48hr of allowed time for payment.
5. Status would change to PAID.
Having said that, my credit fully covered the payment. I am not sure what to do if only part of the payment is covered.
I guess that you would have to wire the difference, which is a hassle.
I am short on time right now, maybe will post the tx screenshot later, but it is essentially the same as described above.
EDIT: the 53Th is gone, replaced by 56th spot pro. I wonder if 56Th would also come from Malaysia. It's a risk worth about $500-600.