They usually won't say anything!! Been there done that. I know it takes awhile but deal with the right people. I feel for you. Bought a dozen eggs from somebody on here years ago, after day 7 all were all infertile. I texted him choice words and never heard a thing. Scout the people you deal with is all I have to say.
I feel like I do deal with the right people, that is why I will speak to them in private first. The person messaged me back within two hours, apologized and offered the next set free, no questions asked. That's what I call a great contact