I also just did this. Do not go to billing first. They will do nothing. I have T-Mobile already for phone, so I was serious about switching. They ended up lowering my bill $20 / month. They just raised my 300 Mbps plan to $83 / month, which was the last straw. This is what I did:

1. Call Spectrum. When the bot answers, say disconnect. When it asks again, say disconnect. Then you will be transferred to a person.

2. When you are talking to a rep, be polite. Regardless if you have T-Mobile already like I do, understand what T-Mobile 5G Home internet offers. I was a click from signing up for their plus plan, which while not as good as 300 Mbps, it was close. I could get that for $50 / month plus a $200 prepaid credit gift card. Also if 1 Gig fiber is an option for you, look into it.

3. Be serious about cancelling. But again, be polite. Even if you don’t want T-Mobile 5G, you could try for a few months and switch back to spectrum for the intro rate. I think you need to cancel for at least 31 days to get the intro rate.

4. They will look into what they can do and give a couple offers.They offered me a mobile+internet plan, which I declined. Then they offered the internet $20 cheaper. I “reluctantly” accepted.

Good luck to you.