for all those who have problems with expired or missed account reonfirmation.
I just managed to reslove the problem the following way.
First I backuped up all of my hostnames and zones.
Second I created another account dynv6 with another email account.
I than closed the old account and luckily I was able change the e-mail address associated to the new account the back to e-mail address of the closed account.
Hope this will help someone else.
However hopefully the team around the services of dynv6 will please fix the issue of the missed account reconfirmation instead of just letting the person with problem just stand in the rain.
How about by adding a smal option to give the person some alternative way of resolving the above named issue.