Internet issues worsening daily

ok so i have had xfinity out to my house at lease 15times in 4 years. started with wifi disconnecting. all lines checked all good. as time goes on i now lose wifi every 20 mins or so and now i also lose hardline every 30-45 minutes. no one can fix and was once told it may be the cable ran in unit.... ummm ok fix it? cant, 3rd party we are not responisble for it. so i am? you sub and get GARBAGE i have to pay? think not. when can someone fix the FREAKING connection issues? now today ive dropped from 750mbs to 230mbs. and i pay 160 a month for this EXPLETIVE?