Predominantly, the Road 5 is advertised as a sport touring tyre, the Power 5 is advertised for those that like a bit of 'sporty riding'. Leaving aside the endless 'which tyre is better argument' for a moment, the Michelin Power 5 is cheaper than the Road 5 (well, around my way it is).
Rough prices near me; Power 5 front is £101 Power 5 rear £130 & Road 5 front is £108, Road 5 rear £139 so not a massive difference overall, but have they actually charged you for the dearer Road 5 and fitted the cheaper Power 5? (If indeed this is the case at your garage prices that is).
Regardless, as broady says, they haven't actually fitted what you asked for. What does it say on your receipt?

(Also, are you anywhere near Kelso? We often pop up there on a ride out for a sausage roll & coffee pitstop at Greggs

).