I felt some attitude in her voice. Either she's having a bad day or the service has been lousy in the past ;)
Well, I don't understand why not use the dative case for "Eine" here since the sentence is actually " i want a cup of tea with milk, please." I remember there was a question with similar structure and it uses the dative case at the beginning.
"Milch" is dative, but it doesn't take an article here.
Could this also mean 'one tea cup with milk', referring to the actual cup rather than the contents?
If not, how would that be said in German?
Most unwise to make this request. In Germany it usually produces a little jug of evaporated milk!