Gotta agree with you esquire. If there was a verbal agreement for free installation and then they decided against it, that's messed up.
The price hike, I can accept that and would have done the same as you (bit the bullet and accepted the hike), but going back and deciding to charge for the installation after being promised you didn't have to pay for it? That sucks.
'11 BMW E92 ///M3 - ZCP and DCT
'15 Ford F-250 - Lariat, 6.7 Powerstroke Turbo-diesel