Claims history download in csv format supposedly excel readable is not

Trying to interact with you via your web site. Specifically, trying to upload a downloaded claims history Excel doc in csv format. Your doc upload will not accept .csv documents. Tried "talking to you" via your “Not finding what you’re looking for?” option and only got the bot which (yet again !!!!!!!! %#*X%@) did not understand the question and told me that it's still learning. Here's the question: I've downloaded the claims history in csv format which is supposed to be readable in Excel. But it presents in exactly that - a string of comma separated pieces of info spread over a number of lines. It requires re-formatting to be intelligible! Why? Last year, the downloaded csv claims history files opened fully readable (although not entirely understandable) on my side with the info split in columns with headings in the right places etc etc. Why does it not do that now? I can convert it but it's a nuisance given previous hassle-free doc opening and the extra inconvenience does not improve negative perceptions of your service. I can send you the file as it opens at my end (but wouldn't have to if you'd accept the document in the same format as that in which you've presented it!)