Yeah, they gave me a link for a free return, but said no replacements as everything's 'randomly selected' 😒 In general terms I get it, but I'm not sure it is actually all that random (see next para for why), plus given the number of dips I've ordered over the years I wouldn't have thought a bit of flexibility would have gone amiss in the interest of customer goodwill. But hey ho.
I have a theory about what might be happening here. The items were all in grey bags with nothing on the outside to give any clue what they were. I reckon that these will have originally been grouped by bag type, though, so for example with my three green Kenningtons (at least, I think they are Kenningtons, but there's just a sticker saying Lucky Dip where the bag info would usually be), because I ordered three items from the same size dip the packer has probably just reached into a box and pulled out the top three items. Which would negate the randomness somewhat, if I'm right. (And, if I am, you'd really think they'd have jumbled the items up a bit beforehand!)
I've heard a few others say they received duplicates too on ordering more than one of the same size dip, which I think may bear out my theory. I may of course be wrong about this, but I'm now thinking not ordering more than one dip of a specific size in any specific lucky dip order might be advisable in order to avoid the possibility of it happening. JMO.