There is contact information on the FDA site. They will direct you to the FDA Director in your state if it's a problem that you have had personally, or let you know if the problem has already been reported.
I dealt with them recently regarding 3 boxes of dog biscuits I purchased at Tuesday Morning. One was rancid, and the other two had active mold. Tuesday Morning Corporate told me that they would "get the information to the right person..." and they would investigate the problem. Concerned about the number of consumers who might make or have made purchases, I inquired about the length of the process. "Two to three weeks," was the answer!!!!
After that call, I called the FDA, who sent me to the NC Director. She promised to get back to me by the end of the day. She did, with the information that Tuesday Morning was issuing an immediate recall that day after confirming the spoiled product on other stores. The very next morning, I visited the TM store where I purchased my boxes, and all of the biscuits had been pulled from the shelves.
It's shocking when any government office works as it should!