Lifeline account misbill at regular plan rate

I was approved for Lifeline as a senior several months ago and expected my plan to change and downgrade based on communication from Xfinity to the Essentials Plan. The Lifeline payment would cover it. Instead the $29.95 from Lifeline posts every month but towards the regular plan I had. I cannot afford the regular plan. Now my service is terminated because for the past two months there is still a balance I cannot afford after the Lifeline payment posts. I have no phone or internet for medical appts. Please help me this is so frustrating!!