Very strange. The sprays you tried should have killed most any pests you might have. You need to somehow catch the culprit in the act so we can determine the remedy that will work best and be safest. Check the plants over in the morning and afternoon making sure to turn leaves over in search of beetles, caterpillars, or other pests. Try going out at night with a flashlight as some pests are nocturnal. If you find any pests send another e-mail through Home Depot's web site and we'll try to help.
In the meantime take care to keep the soil most but not soggy wet as dry or saturated soil can result in plant stress and sometimes leaf drop or shriveling.
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