we dont have any kind of billing system, we are currently 100% local based, we manually do everything, and we only take annually payments...
Never had a customer leave us yet, however, if we did, we send out an invoice, they have 7 days to pay, and if not payed within 14 days we shut off there website...
We also keep a customer backup for 1 month...
But, if a customer finds it hard to pay, we chuck a promo code there way, to help them out
Being there owner, i can choose how to keep a customer, as we are again local based, we deal with all our customers face to face...
However, follow your own terms of service, if in your TOS it says termination after 7 days, stick to it, and dont be afraid to terminate.