Alba, try the duct tape method first, it worked a treat for me with one on my heel.
Cover it with duct tape for six days (if the tape falls of, which it will, just put another piece on). Then soak it for ten minutes and try picking it off, the skin will be very soft and white from being covered and then soaked. Then repeat the whole process...six days covered, ten minute soak... until the verruca has gone. Mine went after the second stint of doing this.
I got this from the patient uk site I think, try googling it, and it honestly does work really well. Totally painless too.