Mesh Scale Not Working?

I am Trying To Rescale a Mesh When It Touches A Certain Object, Here Is What I got And Its Not Working...

function tch(h)
if (h.Parent.Name == "Birthday Cake Blizzard") then
h.Parent.Name = "Birthday Cake Blizzard/w Whipcream"
h.Parent.WhipCream.Mesh.Scale.Vector3 = Vector3.new(0.3,0.3,0.3)
script.Parent.Parent.Spill.Transparency = 0
script.Parent.Sound:Play()
wait(1)
script.Parent.Parent.Spill.Transparency = 1
end
end

script.Parent.Touched:connect(tch)

Says This In Outpu 20:22:24.488 - Vector3 cannot be assigned to