6
For deleting these files, there are two options: install a file manager module, so you can delete it under Apache (with a php program = the module) or open a ticket with your hoster to ask him to delete them. (On one site I faced the same problem and was unable to delete them with option 1, so i had to ask the hoster.)
The export csv is created as /uploads/formulaire/form.csv . It should be deleted after download. (Or set writable, which allows overwrite).
For the list of the sendings, did you select a form with sendings? The number in brackets shows the number of sendings (fill ins) with the forms in the tab consult.
Are there any debug messages?