Hutcheson's in Merchant City, Glasgow.
Went for a celebratory family event (landmark birthday).
Asked to be seated in the downstairs area, as a few party members had mobility problems - seated upstairs. The tables were so close together that I struggled to shuffle my (size 10) bottom between them to get to the loo.
The waiting staff were all about 10 (no ageism intended, but they had the 'deer in the headlights' look of a group of youngsters who had been parachuted in to a job they had once read a book about, but hadn't ever actually experienced in real life).
We waited an hour for drinks orders to be taken, and a further 40 minutes for food orders to be taken and served. When the food was eventually served, orders were wrong three times, my vegetarian dish came dressed with lardons (!), cold food was served on cold plates and when it was sent back, had very obviously been microwaved.
Drinks were spilled over two members of our party (hardly surprising, given the lack of room to serve).
Halfway through, I asked (quietly and discreetly) to speak to the manager, who, while wringing his hands apologetically, offered to take 20% off the bill, which I agreed to (as I couldn't really see what else we could do). When the bill came, not only had the 20% not been discounted, but A COMPLETELY DIFFERENT TABLE'S ORDER HAD BEEN ADDED TO OURS. When I (once again) asked to see the manager, I was told that he wasn't available, but 'in the spirit of goodwill' they would remove the other table's order. WTAF?
We calculated the total of our order minus the 20% and left it, in cash, and left (oh, and they lost my mother's scarf in the cloakroom!).
To add insult to injury, three days later, my OH realised that the refundable deposit taken on booking to secure a large table hadn't been refunded. He called the restaurant and had a 20-minute argument with a staff member, who accused him of lying, before the refund was finally made.
It was so awful, we actually laugh about it now, because it's easier than crying. 