That's a self-created problem. It is possible to remain in business while self-creating problem. It is, however, not recommended.
We once were jerked around by a reasonably well known customer. Their accounting people decided they did not need to perform under the payment terms the customer signed off on. First time they did it, I sent an email to the EVP that signed the order. We got an apology and a payment. The next month the same thing happened again - we redirected all their traffic to "We are unable to process your request - please contact your account coordinator to restore access" message and did not remove it until the wire hit our account ( 5pm-8:02am ). We received a letter with apologies from the customer's CEO, customer was saved and they never missed a payment again. I heard, via the grapevine, that three people at the customer's AP group were shown the door as the result of our message.
We once were jerked around by a reasonably well known customer. Their accounting people decided they did not need to perform under the payment terms the customer signed off on. First time they did it, I sent an email to the EVP that signed the order. We got an apology and a payment. The next month the same thing happened again - we redirected all their traffic to "We are unable to process your request - please contact your account coordinator to restore access" message and did not remove it until the wire hit our account ( 5pm-8:02am ). We received a letter with apologies from the customer's CEO, customer was saved and they never missed a payment again. I heard, via the grapevine, that three people at the customer's AP group were shown the door as the result of our message.