Foil baked onto oven base. (by 2 users)

I recently got a new Westinghouse oven and put foil on the bottom to keep it clean while I was cooking in my second day of use. I didn't realise that there was a botton element and not the foil is baked on to the bottom. I have tried getting it off with a cream cleaner but it wont come off. What can I use to get the foil off the bottom of the oven.