Advice for dealing with Meratas?

This is correct and how the ISA works, and if you get more raises, you'll have to pay more. If you don't feel like your loan was disclosed properly at the time tell them this and offer to pay the upfront equivalent pricing retroactively instead. If you don't or can't pay the upfront equivalent pricing all at once, then you have an ISA for a reason and it's a loan that will cost more than the upfront and the addition cost is the "interest" on the loan.

So the shady part is if misled you to not think this was a loan. If you take out a loan to buy a car or a renovation, or pay down debt, you have to pay it back and these loans are no different except that you pay some of your salary instead of fixed payments so that you gaurantee you have an income when you make payments instead of going to collections becuase you don't have a job. If this wasn't clear when you signed it then you have grounds to complain. The people who settled with Lambda for regulatory violations basically let the ISAs be cancelled and pay the upfront amount instead, or to cap the ISAs at the upfront amount because the hidden interest wasn't properly disclosed to people. If you were misled that you don't have to pay unless you get a tech job directly out of Lambda School AND YOU CAN PROVE IT IN WRITING then you have a case to try tp get the whole thing dismissed but it's going to be hard to prove that if they have paperwork that says otherwise and someone on some random phone call said something ambiguous that made you feel like you won't have to pay. By not paying you are screwing over all of your peers because someone has to pay for the program, so it's not like a screw you them. I would instead focus on trying to reduce the amount you owe and try to settle your account with Meratas for a lower amount than you expect to pay.