There are multiple flavors of this. For example, a debtor can indicate that they don't want any calls at work. (Face it, it is embarrassing and you could face job loss.)
Just because communication may have been halted, that doesn't mean that collection efforts cease. There can still be judgments, etc. Even for those debtors that are really trying to right their financial ship, it can take time. Getting phone calls every few days just adds more stress. I've seen these situations turn around.