Hello, Thank you for using this service, I will be helping you with your problem today.
unfortunately this is bad.using the glass top cleaner and a new razor blade is your best shot. these will scratch easy also. all you can do is keep trying with the glass top cleaner. it may take some time and elbow grease but if your persistent you will get it off. wish there was some perfect solution sorry.
you can order it at the following link. http://ceramabryte.com/productDetail.asp?SID=0CB51852B1B045D08E42EAA6419E2F4A&CategoryID=35&ProductID=44255# b