Granted, its not perfect.

I would suggest you screengrab and keep any recepits you get if you're claiming in this promotion.... and always keep a check on your clicking AND buying history (you can do this after you've transfered to earn.flybmi.com - the screen where you see all the shops) - Click MY ACCOUNT and then follow the links

However, I would be always be extra careful when it comes to points.com. Its a force we don't understand