As long as your account is residential, your IP is probably dynamic - which means that it can change at any time, but the reps at the company most likely won't be able to help you change it.
You can, however, call them and make sure you do have a dynamic IP - I know that Comcast, AT&T, Altice, and many of the smaller ones here in the US all do. As long as you do, you can unplug it for a night so that someone else will grab your IP while your modem is offline.
When I change mine, I usually unplug it before I go to bed and it's changed when I get up the next morning.