Lee, If you a bit more specific (name them), it would be more useful.
Vivek
Yes, sorry, you are right. It was one from amazon UK affiliated seller. I have contacted them and they have offered a replacement/refund. I may try another or just stick with OEM, it was just that I eventually realised that the copy I had was thicker than the OEM and, whilst it went in ok, I gave myself a fright getting it out as it would not pop out easily and I had to hold the spring loaded catch down with a paper clip and shake the camera a little for the battery to come out enough for me to slide it out again!
So, I scared myself. Just beware - if it seems almost too snug going in, best to stop. No point potentially damaging a battery catch on a £1400 body for the sake of saving £40 on a battery!
Lee