[brk-lnt]

Lakeport generally has a good rep, I doubt they were trying to rip you off.

Here is what I would suggest...

It's pretty easy to tell a new impeller from an old one, and they're not that hard to get to. I'd ask them to put the impeller with you there and show you the new parts.

If they look new, it was most likely an honest oversight and something you would have had to have done anyway (and if not, could have caused much more expensive damage).

If they look worn, then I would certainly dispute the charge, and maybe go further than that.

My guess is they did the work, but had some internal communications oversight and forgot to get a formal authorization from you.