If mom and dad said "we're paying for this, don't worry", and then stick the kid with the bill ... that's wrong. Flat out. It doesn't matter if the kid benefited from the education, because they could have just as easily gone somewhere cheaper with the knowledge that they'd have to pay the money back.
I came here to say that as, turns out, that was my exact situation. My parents agreed to pay 50% of my tuition at a really fantastic out of state university. Upon graduation the 2007/08 recession crashed and my parents were hit hard, my dad's salary was severely cut, their home value was slashed, my older sister was getting married to the tune of $40k (ironically, 50% of what my loans totaled), and they had no way to back out of the wedding stuff so stuffed it all on credit cards they're still paying back to this day and told me 'sorry kiddo, you're on your own'.
Now if this guy had a story somewhat like mine I'd be empathetic, but even then, know what I did? Spent a a few days crying in a panic, made sure I landed that minimum wage retail holiday temp job, got the fuck out of dodge and away from my family ASAP (I wasn't going down with that ship), moved in with my boyfriend's (now husband) family 500 miles away and got myself a better paying office job where I was able to prove myself for their marketing work and better pay over the next 3 years instead. Dumped every paycheck into my private loans, sacrificed my 20s living with someone else's family in the burbs of Virginia who were kind enough to treat me like one of their own, started an etsy side gig that allowed my to aggressively start paying those loans back about 5 years after graduation.
Now, 10 years later, I'm not loan free but I'm close- own a home, got married (to the tune of $3500, because I learned that lesson), and work for myself (that etsy side gig has turned full-time).
The thing is, I'm proud of what I've achieved, but I'm not special. Anyone could do this, it just takes some personal responsibility and dedication. I was $100k in debt by the time SM/Navient consolidated my accumulated interest from while I was in school. I never thought I'd be where I am, it's daunting, but absolutely doable.
And you know what? I could hate my parents for what happened, but our relationship is the best out of all of my siblings, maybe because bootstraps and all of that, but I think it's because I appreciate now what they DID do for me, all the more because of what they could not. It wasn't my dad's fault his salary was cut, it wasn't their fault the house bubble burst, it probably WAS their fault my sister wanted a giant shebang of a wedding and they agreed to pay for it, but what are you going to do when contracts are signed and dates are set?
TLDR; Grow the fuck up and get to work.