it surely looks like a scam ... I don't know if skype can really do anything , they get new profiles really quickly and once they get your address ... they will keep coming ;)
Maybe you were too kind to the last one and now they think they have a target that will eventually give in ? Before you know it they will become your "best friends" and want to meet you and make you pay their ticket from South Africa to where-ever-you-live ? :)