Make sure you mention to them that both showed the same fault. Still a chance it's just bad luck you got both the duds, but if the whole stock is wonky, they'll want to have works with the supplier. I remember myself and the fella got a dildo and it had some pretty severe tears, and the replacement was even worse. The chick we spoke to on live chat went and got some random samples from the same shipment and checked them for similar flaws, using our photos as reference. She couldn't find any more with those issues, so it was just bad luck, and dildo #3 is still going strong. But if she had found any more with the same problems, she'd have been forwarding it for a follow up.
I'm sure they'll be happy to swap it for another product, even if there is a price difference to handle, but if you did like the toy while it was functional, might still be worth talking to them to see if there's any chance that you're the same as us, and were just unlucky enough to get two duds in a row.