Change plan

Originally I was on a plan with 200 mbps for ~54/month. I called Xfinity to change my plan because my internet speed was not enough for working from home. I asked the representative  that if I could get back to my original plan without penalty or extra payment if changing the plan does not help with my internet speed for work, and I was told yes. I was told I can get back to my original plan without penalty or extra payment. I changed my plan from 220 mbps to 300 mbps, hoping that would improve my internet speed with my work. However, it did not help at all. After a week or so I called xfinity again to return to my original plan and I was told I have to pay ~ >110$/month instead of my original ~54$ bill. I was told that the original price is no longer available to me and I have to pay more even if I get back to original plan. I'm hoping that xfinity would be able to assist me with this issue to get back to my original plan with approximately the same price that I used to pay.