Personally I'd call in to cancel that asap. That's a terrible deal especially since you don't need the tv so you're basically paying $75 for 75 /10.
The general Rogers retention promo atm seems to be $55 for 300u, $60 for 500u and $65 for gigabit since I've read a couple of people getting offered the same. I was too and took the 300u, asked the reps if there was anything else they could do and got some credits thrown in. It's not the best deal, but it's good enough for now since my promo was going to end soon so I couldn't play the waiting game. If you're in an area with Bell's gigabit fibre available you can use that as leverage and get better promos.
If you don't get offered anything better after cancelling and don't mind switching to a different ISP, Carrytel/Cannet has 150/15 for $50 atm (Carrytel has no activation fees while Cannet is $70). That was my fallback plan and it's better than what you're on currently at least.