Apologies but perhaps I wasn't clear in my earlier response.
I think the confusion is arising because you're seeing the sale period and the free conversion as connected in some way. They're not.
We do occasionally run sales across both X and Pro. As a result, the conversion fee from X to Pro that you see in your account will fluctuate based on the current market price of Pro, compared with your purchase price of X. When you purchased X last year, that would not lock in a future price of Pro, in the same way that when I purchase an apple from the grocery store, they don't agree to swap it for an orange for a set price at an undetermined date in the future.
The only exception to the above is the trade-in offer we made to existing X license holders on the date we released Pro. So anyone who already had an X license could convert that to Pro license for free as a one time thing. This only applies to X licenses purchased before the release of Pro and is a completely different thing to any sale period that we were publicising at the time.
The 3 X licenses you purchased were all post-launch, therefore are not and never were subject to the free conversion to Pro. Neither did we communicate words to that effect.
I appreciate your frustration and of course we would not wish to leave a sour taste in your mouth, however you must understand that we cannot ascertain your intentions when you purchase a license. Similarly we cannot judge what constitutes many licenses to you, as we have people that buy one, and others that purchase hundreds.
Unfortunately we are well beyond any reasonable refund period since these licenses were purchased nearly a year ago, but I do have a couple of options for you.
Firstly, I do see in your account that you have 3 X licenses that are eligible for the free Pro conversion. Whilst they do have have URLs attached to them, they could be switched around to utilise the free Pro conversion if you're in need of further Pro licenses instead of X.
Lastly, since we launched Pro on April 10, 2017 and one of the licenses you have referenced was purchased later that day (after launch), I would be prepared to convert that license to Pro for free as a gesture of goodwill. Please do advise if you would like me to do that.
I hope this clarifies matters somewhat.