shoe soles disintegrating

Has anyone had soles fall to bits from Moshulu sandals?
I bought a pair of mules from ebay , looked unused condition but once I'd walked across the room in them the soles cracked in half. As they were in perfect condition when they arrived the seller refused a refund. I have had shoes in the past where the composite soles have crumbled and manufacturers have said it happens with time as they dry out.
I've learnt my lesson and will not buy second hand shoes ever again.