Nopefully you didn't plant it too deep in the first place; check to see that the soil hits just where the root ball begins, then up half an inch. For a cure, here's my tried & true method: Take a cup of cornmeal for every 2 feet your plant is tall; meaning if the rose bush is 2 feet tall, use 1 cup of cornmeal, etc. but no more than 3 cups total should be necessary. Pull back your mulch, sprinkle the cornmeal on the ground and then work it into the top inch or so of the soil. Water it in well and then cover it with the mulch. Spray your roses with a mix of 1 tablespoon baking soda or potassium bicarbonate and 1 gallon of water. Then monitor your watering so you don't water too much. I have used this method to cure rose bushes that had died back to little more than a stick. It has worked with every kind of sick plant I've tried it on, including little trees, for the past 3 years. This should cure your poor roses. Then put some compost at their feet and use a good foliar feed like Bioform liquid on a weekly basis. You should have beautiful roses in no time.