Once you've fallen behind on your financial obligations, it's only a matter of time before the debt collectors start calling. If it's a bank or your credit card company, then the notices should be professional and hopefully cordial. However, once debt gets passed on to a collection company, the letters and phone calls will likely become much more aggressive.
Fortunately, there are laws in place that give you the power to fight back. The Fair Debt Collection Practices Act (FDCPA) outlines what debt collectors can and cannot do.