No. Debt collectors may not contact you at work if you tell them (orally or in writing) that you’re not allowed to get calls there. Also, a debt collector may not contact you at inconvenient times such as before 8 in the morning or after 9 at night, unless you agree to it.

Additional Resources
 http://www.ftc.gov/bcp/edu/microsites/moneymatters/dealing-with-debt-collection.shtml

http://edis.ifas.ufl.edu/pdffiles/FY/FY22400.pdf