Aviva underwriters ppi 2004. Help!

[Jewels32k]

I am new here and am hoping someone can help me. I had a car loan in 2004 taken with Welcome finance.I was told I had to have ppi to take out the loan, it was also front loaded. I have wrote to them and been told they are not responsible for the sale as it was sold through a broker Pinnacal Financial services. Welcome said that pinnacal were no longer trading so I hit a brick wall as dates were outside the other help I could get (FSCS only deal with 2005 onwards) I decided to check out Pinnacal myself and discovered they ARE still trading, just moved address same director same company reg. I wrote to them and have had a very rubbish fob off from them after having to pursue them after the 8 week limit.They were not regulated back then so another brick wall. So I decided to approach Aviva as they were the underwriters. They have stated they are only dealing with 2000-2003 ppi, at the time I was feeling deflated and didnt ask why. I then rang the ombudsman, who have set up a complaint, but not specifically to anyone yet as they have said I should contact Aviva again and state the things I had said to the ombudsman, like the fact of, if Aviva had not been dealing with an unregulated firm , I then would not have suffered a loss, surely they have some liability? I am beginning to run out of steam, do I really have any chance with Aviva? So frustrating that 2004 seems to be the only year that I can get no help from anyone! If someone can help I would be grateful, beginning to loose my drive to fight this.