The CFPB recommends keeping careful records of any communications from or with debt collectors. Save any letters, text messages or emails they send you, and any messages or payments you send them. In the case of phone calls, write down the exact date and time they call, as well as any harassment or abusive things they said to you on the call. You don’t need witnesses to the conversations, but if an employee or family member heard what the debt collector said, it adds even more weight to your legal case.