Undercarriage clips rip off

Took 2010 Prius into dealership for routine oil change, and after the oil change, was told that the plastic undercarriage panels were damaged and they were trying to figure out if it could be repaired or had to be replaced. Eventually, the tech 'just happened' to find some extra clips in his toolbox to repair the panel.

Here is the BS! Since he had the clips (3 or 4), I wouldn't be charged the $5 per clip. However I WAS CHARGED $56 for labor to make the repair!!! Wth!!! I realize that these clips are designed to spontaneously combust, but does it really take 1/2 hr labor (I'm guessing >$100 per hour) to realize they are broken? The tech has to replace the original clips anyway after the oil change, so how long does it really take to realize they are broken and have to be replaced? I can understand paying for the actual clips as consumables, but the labor is ridiculous. With every previous oil change, I was never charged labor to reinstall the panel. This just seems like a blatant scam to get me to pay $56 instead of $20.

I didn't complain in person because I already knew the head service manager was not working Sunday, but I intend to complain and fight the charge. Does anyone have any experience like this and who did you escalate to at Toyota? I'm thinking about buying a BAG of clips off eBay for $20 so they can't pull this scam on me again. Anyone do this?

Thanks