Problem with Firestone...

I had my tires replaced at Firestone and their technician failed to put my cap back onto the radiator during their courtesy check which led to my engine overheating and eventually failing on. I was given a claim number from the Firestone Store and was told someone would contact me within 24-72 hours to discuss my claim. It has been over three weeks since my claim number has been issued and I haven't received any correspondence from Firestone's Claims Department. I have called the person assigned to my claim and his supervisor numerous times over this timeframe and have left messages after each call. Each time I try to call, my attempts go straight to voicemail. I have yet to receive a return call from either of them. I've tried to call Firestone's Claims 1-800-367-3872 phone number to see if there's anyone else I can speak with about my claim, but every time I call, they tell me an alert will be placed on my claim, but that's who my file is assigned to you and who I need to contact.

I am very frustrated with this entire process. I am also sick and tired of being ignored. Due to Firestone's negligence, I've been without my car for over a month. It should not take this long to receive some type of feedback or status on my claim.

What actions can I take to get some movement towards fixing my car?