If I bought a bitcoin at really really low price because other sides mispost it

[gsemep]

If I bought a bitcoin at really really low price because of there's a bug at exchange service.
 Could they just cancel the deal even trade successfully?
Could they say they just mispost it and it's not true?

[gsemep]

They already seize my account. So what I can do?

[ImHash]

At what price did you buy? exchanges should not be posting anything it's their clients trading and creating sell or buy orders, if you could buy cheap that means there was no buy order above that price, did you buy altcoin?

[Scott J]

Which exchange are you talking about?

I know one exchange did a roll back when a customer made a fat finger mistake - Gemini I think.

[ImHash]

Which exchange are you talking about?

I know one exchange did a roll back when a customer made a fat finger mistake - Gemini I think.

It is impossible for bitcoin price to be very low even if it was a bug as soon as you click on sell all are sold to the highest buy orders down the list.
Unless there was some exchange allowing people to separately put up their own prices and others select which ever they would like.

@OP if you are looking for a way to get back what you obtained unlawfully by knowing it was a bug and still you bought them really you should be ashamed.

[gentlemand]

Yes they can. You don't have any coins until they're in the your own wallet, until then it's an entry on a ledger. If they feel the ledger went wrong then they may well nullify the order.

Mt Gox did this as did Gemini.