I renewed my subscripton to Symantec internet security on july 19,05
upon their request. I immediately receved a confirmation that my
subscription is renewed and that my credit card has been charged $
46.94. I called my credit card and they confirmed that indeed this
amount was chaged by Symantec. Nevertheless Symantec keeps reminding
me every day that I "need to renew my subscription" I tried to write
to them via the emails they provide to staighten things out but this
email was returned as "undeliverable". The credit card has no
telephone for them to whonm I could protest.

Would anybody know how to straigten this out?

In the past this has always been a problem with the Live update software itself. 

On the Symantec web site search for the 'Common Client Update'.
Sometimes it updates and just asks you to restart the computer.

But it has told me before to first uninstall the previous then
re-install it from the web site or download. In case it asks you to do
that remember to copy down product key, found in the 'About' box.

Have you gone to this page and tried to work out the problem?
http://www.symantec.com/techsupp/

Right side of the page is a button called Subscription Support for you to click

Good luck with it all