I was sent a letter that said the following:
Dear Subscriber:

Your delinquent account with us has been brought to my attention for collection.

"Subscription Suspended for Non-Payment", that's what our records reflect.

When we agreed to bill you later, we anticipated that you would forward payment upon receipt of our invoice. A review of our files shows that you have failed to respond to our numerous requests for payment.

Take a moment now to settle your obligation with us and we will promptly reinstate your subscription.

Sincerely,
G.L Valk
Credit and Collections Manager