The Fair Debt Collection Practices Act provides that you must tell a debt collector not to call you at work. There are financial penalties - including recovery of attorney fees and costs (meaning you can probably hire an attorney to handle this for you without charge to you).Here's the rub - if you told them over the phone, you have no written proof. So, next time they call I suggest you engage them in a brief conversation. State, 'Look, you called me, not the other way around. You want information from me, your going to have to identify yourself and answer my questions first.Then ask for the following questions:1. 'What is your name?'2. 'What company employs you?'3. 'What matter are you contacting me about?' (demand specifics: creditor, account type and demanded balance)4. 'What is your mailing address?'If they hang up - which they usually do - call them back and demand to speak to a manger, then demand the same information (above) from them. DO NOT GIVE OUT ANY PERSONAL INFORMATION OTHER THAN THE NUMBER THE DEBT COLLECTOR CALLED. At this stage, if they say they can't help you without you giving them your personal information, demand to know the person's name, company and mailing address.In any event, use the information given to send a certified, return receipt letter to the debt collector stating that they are to cease and desist from calling your corporate cell phone.Then, be sure to download your call log every month. You have to give them time to delete the number from their call list, but once done DO NOT LOSE THE LETTER! If they ever call again, don't answer - just let it ring. Not sure it's them? Search the number and print out pages like this. Then, take the call logs and printouts to an experienced federal-practice lawyer. There are minimum statutory fines (payable to you) for each and every violation on or after they receive your 'cease and desist' letter, plus the law allows the attorney to collect his fees and costs (generally 33% of whatever fines you would receive), so there's no cost to you for representation.Good luck!