O Star lash glue

Bought a lash glue from them. The glue is TERRIBLE quality and they have the nerve to tell me that i don't do lashes correctly. I had 3 clients lashes fall off in 3 DAYS!! how can it be me when as soon i got a new glue the retention issues stopped. They appaerntly used the glue on someone and their lashes started falling out in 3 weeks. Yet there is no evidence. And im sorry but they will just not admit that the product is BAD