[xerophily]

Which company does this related to?

the brand's CS ask me to show them a receipt.

So i guess i only have three options now: BB, Newegg, and Ebay since they are the only three website that sold the model of laptop in US. Which i have no idea which one to choose to minimum the chance of getting order number check 

It's difficult to say for sure, but Best Buy would be my preference.

Alternatively, you can use the corrupted file method, but do expect a lengthy process of repeated requests for the file.

I am doing asus. According to their reply speed i dont think corrupted file is good since they reply my email once every two weeks so that might take like 3 months imo. I am think i will use a bb receipt and just tell them the local second hand seller gave me this receipt when i bought it, or do you think i should just not say a thing, just send in the receipt and until they think i am sus then tell them this receipt is from a local seller? THanks for the advice!