Can't turn off auto-renew - am I paranoid?

[TriumphDriver]

I have 51 days left of a Professional-Plus licence and have just downloaded the new version for Mac, but it tells me that my licence key is invalid, so I can't activate the new version.

No worries, I'm not going to renew anyway, but on checking the licence information I find that autorenew is on. I click on 'Manage subscription' but - hey - Internet access is blocked. All other sites are working perfectly but this link tells me that I need to check my firewall, check network connections etc. Yes, they're all working perfectly but now, when I click on 'Licence Information' up comes the information screen with 'Manage subscription' again, but when I NOW click on that, it closes and takes me back to the previous screen without even trying to access the Net any more. 

I'm not going to become paranoid and complain that Piriform are making it difficult for me to cancel... but... what am I doing wrong? I can access every other site on the Net bar the subscription-management' page? Any thoughts?