In Sweden at least "non payment" is not a valid way to cancel a service. You could end up with late fees and debt-collectors after you instead.
It's a hassle, but this makes companies not willing to go after the debt.
Alternatively, they can do the same as the ISPs around here: jack up the sticker price, then give a large discount - conditional on your permanence as a client for X months. If you decide to cancel, you have to pay them back the discount accrued.