Standard Asalatos are natural products and do have cracks over the surface due to drying. Unless there are any big cracks that affect the sound quality, refund will not be possible. I have used standard Asalatos that crack in a month and I have used Asalatos that last more than a year of vigorous playing.
For TAK TAKs and Muted Asalatos, should you not be entirely happy with your purchase, or you have ordered an incorrect item, Asalato SG is happy to refund your purchase within 3 days providing the goods are in a fully resaleable condition (including the original undamaged packaging)