Cramps are really, really bad signs, that you shouldn't be using these boots. I'm no doctor, but you could be talking significant future health problems.
A skate shop (or skate tech) that doesn't measure when ordering boots isn't worth dealing with.
The sooner you talk to Jackson, without letting the shop get in the way, the more likely they are to help you. I suggest you do it now. It may already be too late, but waiting more, or getting more things done to your boots, will make Jackson less likely to help. At the least, you should let Jackson know the shop is no good, and is unfit to sell their boots.
As an alternative, perhaps Jackson can give you the name of a more competent skate tech within a day's drive, who knows what they are doing?