got there in the end
had to sign up and leave the "S" off the end of my surname though for it to register properly, but it worked so with any luck i'll get the £110 quidco plus the £100 prepaid mastercard, although i did find out that the refer a friend option literally does need your friend to refer you with a specific code.
It's currently £125 quid, so i'd have probably been willing to take that instead of the prepaid card for the extra !
I remember doing it in the past where you could just tell them your friend's name and they'd add them to the order as the person that referred you.
And quidco has just tracked as well