You are overreacting massively. You do not look like "a clown". In the second set of pictures that you've put up (where you aren't pulling a ridiculous face) the foundation is not lasting well, and might be a bit pale for you, but it's not awful. It's not even really bad.
If you aren't happy with it, then speak to her, tell her that you are unhappy with the trial (that's what a trial is for after all), and that you aren't going to have time "on the day" to go through a trial and error approach. A trial is meant to sort out the look you want, etc. Since you're also not happy with her level of professionalism then I don't see what you're waiting for.
Check your contract to see whether you would be entitled to a refund.
On your actual wedding day, if you do your make up yourself put on more blusher than you would usually. I was amazed at how much I had to put on.
Also remember to bring some tissue paper and some pressed powder for touch ups. I didn't do this, so just had to blot with paper. I regret not taking powder, but not that much.
Also, thin layers of make up are much much more effective, and look better as they (inevitably) wear off slightly during the day.