Highly pissed off today

Okay so I've had braces since I was 16 , almost 4 years ! When I moved out at 17 me an DH offered to take over the payments . My mom assured me that she could handle it ! We'll the day comes for me to get them off and I recieve an email saying I need to cancel my appointment because my mom has not been making payments & will not respond to any letters , emails or phone calls! I mean really ?!