Most reputable shops offer a lifetime warranty on the repairs including paint. Talk to the insurance company about your concerns and get any warranties in writing backed by the insurance company that is footing the bill as I am not sure what happens if the shop warrantying the work goes belly up. There are several well established long term shops here in Omaha that I wouldn't hesitate to use.
Also even if they do a complete respray what's to say it won't cr-p out in 1-5 years ? A lot of them anticipate the customer not keeping the car for that long


Edit

if they didn't listen to you the first time, I'd find another shop

Also it's the metallic you would be concerned with not "metal flake" mateal flake was ppular in the 60's- 70's Think boats with big flakes in the paint