Product fell apart, Customer = 0

Bought products, external packaging in my opinion everything was okay. Connected to my Rollei, the other end into the cigarette lighter. All the time there left when I got it out once taken, the other end fell apart literally, as it would have been already broken. Complaints does not help, I'm in the burden of proof, should be a indipendent appraiser ?? order and pay, it will not even received nearly upon me ....
I know that I will no longer buy from this seller again.