In 2010 we finally decided to replace our ancient, tiny, nail varnish coated television for a decent size one for watching Netflix on as we don't get any tv channels here. It was the biggest purchase we have ever made, and we used a combination of savings and gift money to splash out on it. We hadn't planned on getting such a big one, but got a bit carried away in the store and I was persuaded by the idea of having a life size Robert Downey Jr. in my living room whenever I fancied 
. We were also lied to repeatedly by the sales associate and bullied into buying a $430 protection plan, that he claimed covered everything except theft. Including accidental damage to the screen. We asked several times and he confirmed each time, we were covered and wouldn't need additional insurance as the protection plan covered everything.
The inevitable happened - the screen broke, and then we realised we had been lied to - we researched online and found a website with a forum for staff and ex-staff discussing how they were encouraged in daily meetings to lie and bully until the protection plans were sold. It is clearly a common practice and the only way the staff made a good wage so our associate had a lot of incentive to lie to us.
I need to write a letter that gets across how upset and angry we are, how we were lied to by the sales associate repeatedly and that, because of his lies we never took out additional insurance which we obviously would have done if he had been honest. He was also supposed to give us a protection plan booklet which he didn't.
I want to make it clear that at the very least we want all of the protection plan refunded, since it was mis-sold. Ideally they would replace the tv as we were told would happen, but I realise that won't happen.
How can I word my letter that makes it clear I will happily picket daily outside the store with big signs calling them lying scumbags if they do nothing, but whilst being polite enough so if the manager has a good will gesture option, he might use it?