Took my car in for a routine oil change, brake line started leaking fluid when I got home

I have a 2014 Kia soul, 125k miles. It’s old, but I take care of it and it has had minimal issues.

i took it to the same place I always have to get an oil change. On my drive home, my brake felt extremely off. I had to put a TON of weight on my brake in order to stop. I let it sit for a bit and then an hour later the same thing happened and my brake light came on the dashboard. I call the place and took it back. fucking terrifying 10 minute drive because I thought my brakes might just go completely out.

they told me that it must’ve rusted and been rusted and when it went on the lift to do the oil change it finally snapped and started leaking. $350 at least to fix.

How likely is this…? did they fuck me over?