Front Gate Tickets Sold My Personal Information to Ad Agencies Internet

I had no other choice than to use this third party service to purchase tickets to a particular concert. When purchasing the tickets, the company required that I provide a phone number, but included a statement that they would not sell the information. I am very selective about providing my phone number, and decided to trust in their statement. However, within 2 days of providing the information, I have begun to receive multiple calls daily from various telemarketing firms. I've held this phone number for nearly 10 years, am on the Do-Not-Call registry, and have never received calls from telemarketers in the past.