You may well have done I think the counter was broken for a while. For instance my completions of crota + vog do not add up to the number it says I've done. I have far more completions than it says......actually I probably don't want to be shouting about that in case people start thinking I like being tortured! I've lost count of the number of times I've done it to help others out....oh right my brain has just pointed out that completing it 6 or seven times in a week doesn't count as it only counts once per character.