This criteria needs to be met
"I’m sending out this email because you donated to Just Giving page for our 2016 charity livestream above the value of 6£/€7/$7.5 and as such, you have received a free SpecialEffect Sidewinder paint job and SpecialEffect Decal. "
My email(s) had that exact content in it along with the other things, but it didn't have the code. Fortunately, a ticket later and I think it's all sorted out. I'll need to check once I get to a shipyard.