Hi Benoit,
Thanks for reaching out with your Total Upkeep Premium concern. I’m sorry to hear you’re having trouble but I can assure you that the Total Upkeep can be used on unlimited websites as long as you are the website owner and not using the plugin for a third party.
If you would like a refund, you can reach out to our Premium Support and we’ll take care of that for you.
I hope this helps. Please let us know if there are any other questions we can answer for you.