Did you ask why they did it? It's your yard...you have a right to ask why they've wasted your time and money.
If you want to keep them and give it another chance, walk the yard with the landscaper before you leave and say "Please do this, don't do that". You can still be nice about it, and still be clear at the same time. I've had a little experience with different landscapers and walking the yard is always the test to see if they listen and care. If they don't.....then I find another. But usually they do because it's their livelihood and most people want the customer to be happy with results.
