If your open orders could not be cancelled:
pls submit a ticket, provide the order details or error prompt if any. Will check and handle for you soon.
Why my order/trade could not be executed/traded?
Pls firstly check your order price and volume, compare it with the current market price to see if your orders is competitive(details, pls refer to below). You could keep wait. Or you could cancel your open order, adjust it as per current market price to expedite order execution.
If you are buying: pls check the current selling market orders(Orders in red), your buy order will be executed partially or fully when it matches selling orders. Otherwise, your buy order will show as open order in buying market(Orders in Green).
If you are selling: pls check the current buying market orders(Orders in Green), your sell order will be executed partially or fully when it matches buying orders. Otherwise, your sell order will show as open order in selling market(Orders in Red).