I agree with this post every time you get a new frog there is going to be a period of time it wont eat due to stress. So take CPLfrogger's advice along with putting your frog in a room were it will be distrubed as little as possible. Make sure you have its required humity, temp and setup. Then just give it the right size of food and give it its privacy.
When i got my cane toads it took almost 2 weeks for them to eat and these guys are probably the most resilient amphibian species i can think of.
Just give them time. you will be very surprised how long a frog can actually go without food. So dont worry about starvation.