Disable the Port-Scanning warning. It is useless! It only drowns really important stuff! Port-Scanning is not an attack. Nothing breaks because of a harmless port scan and an alert does not provide you with ANY useful information. So get rid of this useless piece of software.
Your ISP is doing nothing and rightly so. It would only suck up resources that can be used elsewhere where they make a real difference!
Fighting port scans is like trying to fight people looking out of the car windows! Get over it, ignore it, it's completely normal!
And don't suck up other peoples resources by whinging about it!