Too much to ask for?

On Sunday 17th May i ate at La Romantica, a restaurant where i have had many great meals and good service. With the steak I ordered I asked for a salad, but requested if i could get a small portion of Caprese instead of the Greek salad. i was told i have ot pay for a full extra salad if i wanted that. I explained that all I actually wanted was some tomato instead of the Feta. This resulted in the involvement of the waiter and the manager and the unseen kitchen manager. Eventually i received some tomato with some chees that had been hacked off. The food was good and I received what I asked for. My question is why must the staff be unfriendly because I have what is a small request and need to involve so many people. I understand restaurant costing etc, but I did not ask for more than a small portion. If it is too much trouble for you to meet simple requests, then maybe it is tme for me to move on to other restarants that go out of their way for clients!