Oh that's strange as I entered the details on the ww calc on my phone I had 15g, is there anywhere on the ww site or app that gives you points info like a list maybe without having to enter all the nutritional info?
If you have a iPhone u can, on the Ww site of you have access to the tracker just type in Heinz mayo on the add to tracker bit and it'll give u a list of Heinz mayo, have just dbl checked with portion as 15g and it still said 3,