Travelup Charged Me After I Canceled My Hotel Reservation Online

I canceled a hotel reservation using Travelup's website, but I didn't get an email confirming that it was canceled. However, when I checked the website later, it plainly stated that the reservation had been canceled. I even took a screenshot to make sure. Still, they charged me anyway when the original payment date rolled up. I called customer support right away, told them what was going on, and sent them the screenshot. The agent continued saying, "Don't worry, the reservation is well confirmed... you're good to go," instead of rectifying it. It was as if they hadn't even read what I wrote. They didn't care how many times I told them I canceled the booking. Not helpful at all and quite annoying. Travelup needs to take charge and really pay attention to what their clients say.