I will decribe very shortly my experiences with VeriSign and their web service they offer.
I tried to cancel this service 05/03/02, received no answer, but they carged my credit card account again.
I cancelled a second time 06/04/02 and 'till today, no response.
And the best of all comes now:
During the cancellation process on their website you get finally informed that your domain name will be erased, too. Not only your account, but (generously) they offer you that you can buy it for ONLY $25.00......what you did already as you signed up for their service.
So please stay away from them or sign up with them if you want to get fooled and feel like an idiot.