Was asked for my Order Number and he sent me an RMA instructions email. Checked details and he had written that my fault was memtest86 failing which wasn't the case at all. So I rang to clarify and he stated that they won't recognise RAM as faulty unless it fails memtest86. I was quite surprised so I started pushing him since I know one of the sticks are faulty. He basically ended up telling me to follow the RMA and they will send me new ones regardless of the memtest86 policy :S.
I only queried it because I didn't want them to get the RAM, test it and then say "There's no errors, no replacement for you". Apparently it's unlikely that they will even test the RAM, instead they'll just send me 2 new sticks. As long as that's the case then I'm happy
Labelled and sent from work today. Hopefully will have a quick turnaround time since I'm currently borrowing flatmates old RAM sticks.