Lost Grandfathered plan without my permission.

A Xfinity in-person service technician working on my internet line noticed my cable box and mentioned that I could get rid of my cable box and remote to go 100% streaming. Also, keep my monthly cable package as-is and save rental fee for the box. I called phone rep. and disconnected my box as suggested by in-person technician and tried Xfinity app 100% streaming. My monthly package did not change during this period.

I did not like the app (seems more beta) and decided to have my cable box turned back on, so I called the phone representative. He did not mention my monthly package was grandfathered. Also, confirmed when I asked there would be no impact to my monthly package.  After 1-2 weeks my box had not been activated and the cable package remained as-is with app, so I called back on 11/07 to have it turned back on. The rep. was able to turn back on my box, but did not mention that I was on a grandfathered package nor that I would lose my package. She confirmed when I asked that package would remain as-is. Two days later I notice that I lost major channels and reduced DVR storage capacity size. I called back and then was informed that I was on a grandfathered plan and that the package I received is lesser than what I had at the same cost and if I wanted back my original package, it would cost me $50 more than what I previously paid. THIS MAKES NO SENSE... Why would I agree to pay $50 more than what I used to pay when I was trying to save $10. The rep. told me there's nothing they can do and I'm wondering is this Legal? I've been a loyal xfinity costumer for 11+ years. I don't know how to resolve this... Is there someone who can help? Currently paying for a lesser monthly package at same cost of my superior plan.