He is probably not eating due to the stress of being transported and put in a new home. In a week or so, he should feel secure enough to eat. I would not worry yet. 
I don't see why they told you not to feed crickets! They are the best food source for small horned frogs, in my opinion. If you're concerned about the legs getting stuck, you can either buy smaller crickets or tear the back jumping legs off (the cricket, not the frog, heheh.)
What substrate (tank floor covering) are you using? I use a coconut-fiber bedding that goes by the name eco earth, bedabeast, or forest bedding. H.frogs like to burrow into this. You might want to put a flat dish or saucer in for feeding time, though, so the substrate does not stick to the food and the frog's mouth.
Also you need to have a shallow water bowl for the frog to soak in. Make sure the water level isn't over the frogs nostrils, and also be sure that it is easily accessible (sunk into substrate.) These frogs are not particularly good at leaping.
I'd ditch the heatpad and buy a heat lamp. You can adjust it above the tank to attain the right temperature. Heatpads under the tank are bad cuz the frogs burrow in order to escape the heat, not to go toward it.
What kind of tank do you have the frog in? I'd get a ten-gallon aquarium and use that, and it'll be good for your frog's entire life unless it's a huge female.
Here's a pic of my horned frog; lives in a 10g, since I got her years ago, eats nightcrawlers (bait worms) and crickets...

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*~Ginevive~*