When I got my Tobeco clone from Ebay one of screws on positive block felt very loose I tried to screw it back in but is spins freely it's like thread is stripped. I ordered new positive block from FT and some o rings because mine leaked a bit and it came without any spare parts whatsoever :-( .Otherwise it works fine
I don't have Infinite version but my friend has one and he is very happy with it
Did you contact the seller because they for sure will take care of it?