Haven't used it myself but isn't the last call in the api doc (
https://www.hashnest.com/hashnest_api) for the order list? Not sure for withdrawals/deposits though...
EDIT:
https://www.hashnest.com/settings perhaps check if your IP settings are accordingly for the api call? (probably not possiblity for wd/dep with api calls since you can't even choose that here...)
the last call is quite confusing!
it looks like the order-call, but it gives a list if all trades in the past. so you can only see what happened in the past, you can not see the orderbook!