How can I cancel an order

I believe you cancel it from within the order itself. I have never done this before but I have seen the option there. If you have any difficulties then contact support.

I'm not sure if you can request a mutual cancellation from your side since the order hasn't started yet, so I think you will need to contact with the seller, and explain to him that you mistakenly purchased that service.

Or you can contact directly with the support team.

Support: Help Desk
Email: support@seocheckout.com

Thank you,
Procoder

Contact the seller and explain the situation. Usually, if the sellers didnt start your order there is a chance to get your money refunded. If not, let him know that you will write a support ticket.

Thanks for your replies... The order had been canceled by staff but they didn't refund me. I think I will contact them.

If the order has been canceled you should have got your funds back too. Are you sure they aren't showing within your balance? - They might have been refunded in the way that you can't withdraw the money. - If you can't see the money in your balance, just contact the support and they will look into things.

I think you can inform the seller about this, and explain that you ordered by mistake. You can then hope to reach a mutual cancelation agreement with him or her.

The funds might not be refunded immediately. Probably there could be some time to wait.

The order can only be canceled by staff or by you by submitting a mutual cancellation request. But for you to do that you must reply in some wat to the seller's requirements so that the order will be mark as active and the mutual cancellation feature to appear.
As a seller, I always get buyers that didn't really want to order my services or changed their minds at the last second. It's perfectly understandable and I never hold any grudge on the buyer.