Literally just had the exact same conversation. I had been paying $124.99/month for 1 Gbps, which was part of a "promo discount" for 1 year. Now that the full calendar year has elapsed, my bill just went up $20. Spoke with a Billing rep today and asked to drop down to 400 Mbps and was floored when he told me it would only reduce my bill down $20, taking me back to the same amount that I paid for 1 Gig speed a month ago.
I told the rep I was highly considering cancelling, yet he declined my request to speak with the Retention Department. However he did tell me if I call back on a few days before my billing cycle ends on April 2nd and zero out my balance (even though I'm on auto-pay), that I would fit the criteria to be able to speak with Retention on negotiating a better deal. Still a load of BS, but sounds like this is the only course of action. Hope this info helps others.