[notanlines]

I concur with most everything said so far. It would be my opinion that you do have enough truck (not by a lot), however, you will need to lower the ball on your hitch. As Danny and a couple others mentioned, your truck is WAY out of whack level-wise. The company you bought your hitch from (Blue OX) should be able to fix you up on a different hitch with the ball about 6" or so lower than what you have. DO NOT give up on the stair issue. You don't need any coupons, nor do you need any pizza. And as KSH said, look mighty close underneath where the blowout took place and inspect for further damage.
No, you will not look back on this one day and laugh. I hope instead you will take to social media and report your happening, both good and bad, about this dealer. They are surely deserving of your wrath.