Спрашивают в личке. Так что отвечу сам себе.
Через день после письма в поддержку всё зачислили.
Образец письма с okex
I, (customer name), from (Country) Passport/ID holder with number XXXXX, deposited XXX (Amount) of (Crypto token) on Date (DD/MM/YY) at Time (HH:MM), into my OKEX account, registered with (mobile number/email ID/phone number/email address).
The token didn't arrive at my OKEX account because the correct tag is missing. I hereby declare that the details furnished above are correct and once the token is credit into my OKEX account, the case is considered fully resolved.
full name and date