Can't register product

I can't register my product. It said "This Serial number has already been registered in our system".

Yes I buy this from online and it is a second hand itme (Who will never buy a second hand and cheap products?). But I really cannot believe your product's warranty cannot pass on from previously owner to the current owner. Change owner means change product to you? 

The serial number can easy show every product's warranty information in your system, I cannot understand why you need registered owner to claim the warranty? you leave the trouble to customers and make your work easy? 

If you said you just wanna keep safe to the registered customer, I can understand this will work for who have hard driver with products. For customers who just using your products without hard driver, this is unbelievable policy.

And also I found your company is hard to contact. I cannot find any direct way to email or call. if I wanna call or email I need a registered product. like a strange circle.