definitely had some sort of help, whether it was some sort of excessive heat or customer cleaned it with some sort of harsh chemical. how many of those numbers do you have to make? in the grander scheme of things i would say you won't have to shut your doors because you made new numbers (i would hope there was enough profit in the job where that won't make a difference) but i would also tell the customer you aren't replacing them again and explain to them the proper way to clean it.