You are not addressing Apple here. We are other end users with no more access to Apple sales records than you. No one here can investigate this on your behalf. You need to contact Apple, as they will not see your query in this user-to-user setting.
If you have multiple addresses, check them all for purchase-related communications from Apple.
That said, from observations here, I find that a very common cause for such cancelations is that you tried to order from the US online store but your shipping and/or billing address is in another country. That policy is published in this Apple shopping help article:
Shipping & Pickup - Shopping Help - Apple
under the section, "Shipping Policies."