Problems with subscription renewel

Have just had a session with the chat line.  I was asking a question as to why a notice that my subscription was running out when it wasn't due for some time.  After several red herrings I found out that I had two accounts  After several more red herrings I then found out that according to Norton I had sent an email asking that my account should be transferred to my sister and giving a name and an email address, neither of which had I ever heard of and I also don't have a sister.  By this time the issue had been upgraded to level two.  I got the same answer.  When I said that I had never sent the email I was told that they had validated it and also validated a telephone call from someone about the transfer.  When I questioned how they could validate it without checking with me I was met with silence. I then got the same message again that they had validated it.  Started to feel a bit like going round in circles getting nowhere.  Have tried to find out how to make a complaint but without any luck.  Has anyone got any suggestions?