Refund paying for blast $107+ per month. Technician checked service at my home and said I only have the 400mbps plan

Paying for the blast $107 plus fees monthly. The technician came to my home to access why we are getting dropped and slow internet continuously, despite a new modem capable of 900mbps. He informed me I am getting the plan with maximum 400mbps. Since he checked with his equipment, I want reimbursement for years of paying for blast and not even connected. I have run speed tests never greater than 160mbps. Now after visit confirmed that not getting blast. At the least I want reimbursement for my monies paid and you not providing what I paid for.