Regarding a sale to a brand new member

[nocontest]

So I just recently sold an item a few days ago to a brand new member with 0 feedback. The item was a "pre order" and will be shipped after I receive from a third party. After speaking to other sellers and experiencing things myself, it is quite common for buyers to apply for a cancellation or message me on some other grounds to refund them. I , as well as other sellers believe these are "dummy" accounts created to temporarily remove our product from the search results to better increase their chances of selling their item. 

The item sold Saturday and I immediately reached out the new account buyer ( with 0 feedback ) to start communication to verify the sincerity of the purchase. After not hearing from them over 24 hours I sent a follow up message. It has now been over two full days without any response. 

So my question is:

Is it within my right to cancel the transaction (with a brand new 0 feedback member) if I have not heard from the buyer after making several attempts to contact him/her?