Double My Speed - Triple My Headache!

I heard on the radio this morning an ad for "Double my speed".com (free trial). It told me to run it....and it turned out be "Cyberdefender Registry Cleaner"....well it is not free....they want $39.95/year..... I tried to uninstall it from my computer and I can't do it. I call two times to Cyberdefender (866-793-0453) and was told to go to a site www.Cyberdefender.com/remove and follow the instructions. I did exactly what the instructions said and it still won't uninstall. I am so mad and upset with myself. How could I fall for something like this. It still keeps bopping up on my screen. When I called I asked them if this has happen to anyone else...they said No...it might be your computer. I don't believe them!!! Could anyone help me. Please....