How demoralizing...but that sounds like a major construction malfunction and nothing to do with you! Can you march those back to the store or get on the phone with CS?
[FWIW, Mr Vix just had a huge rip from zipper zone to top of thigh happen with a pretty new pair of hardy Dockers (or whatever), and it was nothing to do with body shape...luckily for him I pointed it out before he left the house. But I was all "WTH??"]
Re the boots: Apparently the calf-stretching is pretty specialized; I have tons of shoes stretched in the instep/toe box zone and my place can't do boots, sob. But do call around.
Unfortunately I am in that place of too big for most regular boots and too small for the majority of extended-calf ones -- sounds like I'm not alone?
After years of frustration I know my exact calf measurement and won't order unless the circumference is +3/4 inch (with preference for a hidden stretch gusset). And after years of frustration I also get down on my (booted) knees to give praise for online shoe shopping!
When boot shopping at B&Ms I whip out my tape measure first and reject the suckers that won't work before they can reject me -- yes, I am THAT crazy woman but at 41 I've learned how to reduce heartbreak a little!
I'm not keen on most pull-on boots but last year I did find a pair that I liked, so don't rule (more of?) those out. But please please don't rely on boots to "stretch out;" I wear my boots HARD and after years 2 pairs have *maybe* stretched 1/2 inch. One borderline pair is still super-tight but dang they look good IMO, so I stupidly keep wearing them, ha.
Good luck!