Don't get ripped off by Spectrum ISP

I don't know if this is nationwide, but at least in my area Time Warner Cable has been taken over by Spectrum. I've been thinking about upgrading my internet speed for a while, so I called in hoping they would have some kind of deal. No luck on that but I decided to upgrade anyway. (Speed has been even crappier than usual since the takeover, suspicious...) So the girl I spoke to told me that my current modem wouldn't be compatible and I would need to get one of theirs without even asking what modem I had, which maybe should have been a red flag. But when I asked if there were any additional charges associated with the modem she said no so I figured why not. Luckily for me she never even put the order for the modem in. After contacting them 3 times and being told at first that she had been mistaken about shipping time, then the following 2 times that it would be arriving that day, I called in and finally got an honest guy who know what he was doing. He asked why I was't just using my current modem (which I purchased, not leased from TWC), and when I told him he checked that it was in fact compatible and capable of handling the higher speeds and processed my upgrade right then. Then he commented that that would save me an extra charge and take my bill down to $65 a month from the $80 I was quoted by the first girl! I don't know if that would have shown up on my bill as a separate charge or just been rolled into the total where I never would have known, and it really pisses me off when sales people lie to your face when you ask a direct question. So beware, if you're not using your own modem you're probably paying for it, whether they told you so or not.