Contract - No Easy Exit to Prepaid

Somehow I wandered into a 12 month contract for internet.  I am 2 months in.  I asked the store rep to switch me to the new $30 now prepaid plan when I heard about it..  He told me I had to pay $120 exit fee from that contract.  I guess because the now plan is prepaid monthly.  Asked if there was a 12 month prepaid plan.  No!   So I trapped myself by accepting the 12 month contract.  Be careful if you are thinking of changing to prepaid from a contract.  X wants $120 exit penalty to go prepaid.  I would save $ over the remaining 10 months but the I have to get the ‘used’ equipment that X tells you they will never service. And will charge you to replace.  So I saved $10 for a  few months and now they want $120 from me, a 10 plus year customer,  just trying to take advantage of their new offerings.  I was told, many years ago when I signed on, one can always switch plans as long as one stays with Comcast. No!