WOW! Where do I start??

WOW! Where do I start??
So I booked thru Kayak/Priceline--all was great. I paid $167 for 2 days and a couple hours for my rental. Once I got to Advantage at the airport they offered me a free upgrade--great! I accepted. I also accepted $9/day insurance. An extra $27 no biggie, right? Turns out I got charged an extra $355! Excuse me?! For what? I'm not sure. I tried calling twice and hung up after 15 mins of being on hold. I then called a 3rd time and got to customer service after 15 mins. Too bad i could hardly understand their customer service rep. Oh, and she couldn't help either. She submitted a "ticket" for me and said someone will call me to discuss my situation within 24 hours. It has now almost been 72 hours... still haven't heard from someone. Oh and did i mention that I'm trying to call them AGAIN as I write this review? Yeah, I've been on hold for 41 minutes (so far) and I have yet to speak with a human.