HELP.... I cannot activate the product I just purchased

OK - so tell me how to fix this mess..

 

1) had Norton provided by my horrible ISP (COMCAST).... which I discontinued service with.

 

2) I paid for Norton on my own - and cannot activate it now on this PC because the version keeps coming up as COMCAST.

 

3)  SO???????????????????????  What the heck do I do now?

 

I have the product key in an email but I cant put it in because the COMCAST version is interfereing. 

 

Any suggestions?  Other than wishing instant bankruptcy on the idiots at COMCAST?