The great gift shop stopped me giving the tea room...

The great gift shop stopped me giving the tea room 1 star. Lovely restaurant serving what looked like lovely food but the service today was pretty shocking.
We are a family of five and we waited in the queue with hungry kids for probably 25 minutes to be seated. The manager suggested taking the kids to the museum to kill time while we waited as they were 'trying to catch up'. When I came back I spotted a recently vacated table that was subsequently cleared. Several minutes later I pointed out the table as I didn't think the manager had noticed it, she nearly bit my head off and insisted on making us wait for another table.
We only ordered drinks and a cake each but the cakes turned up long before the drinks. One drink was missing, as was the milk and one cup. We immediately told the waitress and she just walked off and did something else. I had to go to the counter myself as my tea was stewing and I'd already eaten half of my cake.
When I paid the four staff behind the counter looked sheepish at each other for a while then went to fetch someone who knew how to use the till.
There were still people queuing when we left but half the tables were empty. There seemed to be plenty of staff but they just weren't organised. I don't know how they'd cope if a coachload turned up. Shame.