So allegedly Amazon UK sold some AMD A8-7600 APUs, but they actually shipped Athlon 64 X2 5200+ CPUs. Despite what you would think, it was actually “dispatched and sold” by Amazon UK itself, rather than a dishonest seller who has some explaining to do. For those affected, Amazon is apparently handling customer service well, as expected, and promptly replacing the parts. It does not seem to affect other regions, and the problem started just a short time ago.
Unless you're Sebastian, these processors will not even fit in the motherboard socket. PC World has an interesting side-by-side comparison of the two pin configurations. They do not look alike at all. You should not have a hard time identifying the problem if you are careful enough to look before you insert, which is obviously something that you shouldn't have to do. Also, AMD refers customers to their authenticity support page for a few extra ways to be sure that the box that you got came from AMD.
What would be the most interesting part of this story is finding out what happened. Unfortunately, we probably will never know, unless it turns into a famous legal battle of some sort.