I understand why, I never expected you to have such an easy time sending it back.. but thats actually better than the kind of service ive come to expect from china.. I know oh so well, Ive had vendors on alibaba do entire runs of custom designed equipment and fuck its a hastle, but worth it for the cost.. for me to make a couple hundred custom wiring harnesses in house would of taken me thousands of dollars in man-hours, I sent one to them with some cash and eventually they sent me back a giant box full of wiring harnesses for a couple hundred... I have to assume an army of kids slaved over them, but thats free trade for you.
the US vendors I buy Dahua from such as Wrightwood would have hand held me through fixing the focus once I had explained the issue... I even had one arrive with a cracked glass around the IR and they cut me a great deal on an upgrade for the hassle.. not there fault some shipper abused the damn thing and I was glad with the upgrade they talked me into.
I think you got pretty fortunate, despite the smartass remark he made..