Aliexpress I bought a laptop from Aliexpress I am not very happy with my order as they don't want to refund me

Aliexpress I bought a laptop from Aliexpress I am not very happy with my order as they don't want to refund me. Canada post and Aliexpress say it is delivered but until today I didn't receive my laptop that I ordered from them they don't want to refund nothing so I have proof from Canada Post to say that if they don't find the package by the 14th of April then I must contact the seller. The seller is also nowhere to be found as it doesn't reply to anything nothing so what is going on