Ann, your window wells should not be filling up with water. Is it just one or all of them? The pipes in the wells are connected to the drain tile system going to the sump pump. The newer pipe has a netting around it to keep the pipe from plugging up with fines. Fixing the drainage away from the house is the first step. Also make sure your sump pump outlet pipe and roof drains extend away from the house so you aren't just pumping it around in a circle.
If your wells fill up, then you have a lot of water next to your basement wall that should be checked out by a contractor in your area and fixed before it leaks or breaks through the wall. Get a post hole digger and dig out a couple feet in the window well. Check the water level in the ground and check to see if the pipe is plugged and put a hose in the end of it to see if water runs directly to the sump. Also the bottom of the well should have at least 6" or plenty more of gravel for the water to quickly soak through. Where are you located? Is this something new? Do you normally get lots of rain or is this El Nino or La Nina related?