I had an exchange deposit like that once, it was a website that had not updated their fees since 2013 so they honestly wanted I think it was 0.1 or 0.01 BTC as a charge to withdraw.  Their argument was we've never raised our prices so you have no grounds to complain, problem being BTC had gone from 50 to 1000 in that time so it wasnt close to fair.   Not uncommon a situation unfortunately, when ETH was $4000 I was not allowed my 0.1 ETH because its too small to handle, so either ETH is broken or they are very lazy.