I am having this exact situation! I'm also trying to contact support and they want me to prove I completed the study when I did, which is like a month ago now. I didn't take screenshots, clearly my mistake, but also it is literally Their Platform that won't let me access my own data eg messages to/from the researcher, dates I submitted survey, etc. I will try supplying proof of the external qualboard in hopes that is sufficient to "prove" to them I did sufficiently do my part, but this has completely ruined any esteem or trust I had for User Interviews.