freecreditreport.com freecreditscore.com Quick to take money, impossible to cancel... Internet

Been trying to cancel freecreditreport.com for my grandparents for a while now. My grandfather accidentally signed up for this ripoff of a service when trying to research a negative item on his credit report. They have been billed 16.95 every month since. 

You cannot cancel online. It says you must call to cancel. Fine, I know why they do this; it is so they can talk you out of it or sell you something else. 

Problem is, I have been trying to call for the past week and each time I am told "Due to high demand, we cannot take your call at this time. Please try again later." At that point the call disconnects. 

How in the **** am I supposed to cancel this if they won't let you call? Clearly this company "traps" you into being a permanent member.