I'd pick up the phone and complain. I know that's an alien concept anyone born after 1980, but you'll get a better response than email or leaving a bad review, as its more difficult for them to ignore it.
Additionally, on top of any goodwill gesture/voucher, it will likely remove that garage from their list, so others won't hit the same issue.
Personally, I've never had any issue with BC fitters, once back when I had Tractor they took 30mins to do one tyre, most of that was due to starting late, but could accept that (despite the fact I was at work

). They have recently opened their own branded/franchised fitting centre at Tesco near work, which I've used once. Turned up 10 mins early as requested, went in at appointment time, about 25mins later I was driving back to the office car park with a pair of boots on the back.
I do tend to use fatty in town when I can though. Partly to support local Brakkers businesses, but also he then becomes "responsible" for the tyre throughout its life, so when it sheds a weight, or if the rim starts to leak, he'll sort it. He will, like any independent tyre place, match any online
fitted price when presented with evidence of that price. Downside is he sometimes needs 2 attempts to balance them... ...though that hasn't happened for a while as he's learnt that the Omega seems fussy on balancing, which I always remind him about anyway.