Convince my parents I DON'T want a smartphone?

[Loopin]

So my whole family has iPhones and I'm the only one still holding on to a relatively "dumb", 5yrs old, Samsung feature phone. I'm going off to college next year and my parents insist on me getting an iPhone, supposedly so they can find out where I am using the "Find friends" service.

I don't mind my parents knowing where I am (I'll be far away from home anyway) but I'm not keen on splurging $$$ on an iPhone and data plan that I'll never use for anything except making calls.

I'm a very weird 17 year old, I don't text or Instagram or use streaming-music or have random urges to go online, so my dumb phone serves me well. This is because I actually had an iPhone at one point and it distracted me so much at school that my grades went down and it literally damaged my social life AND my eyesight.

Since then I have refused to even consider touching an iPhone and strangely my parents aren't very pleased with that. I might be the only teenager in the world who would fight with the parents not to get an iPhone, not the other way around.

They don't understand me, how do I convince them?