Hi!
First of all, apologies for any potential misunderstandings, I have translated your message as I am not a French speaker. In addition, I'd like to apologise if your experience with us was not what you expected it to be.
In regards to the expiry of promotional credits, this is a timeline that is communicated with all partners that we work with so it's possible that they did not advertise the validity period in their particular advertising. If you're able to reach out to us via our chat or email (support [at] upcloud.com) with some more details, we can take a look at checking this with the particular partner.
We would never remove referral credits from a user account unless there was an issue, or if there was a genuine human error whilst handling a case. In every case where a mistake is made, we will correct it once noticed. If this hasn't already been rectified for you, again, please reach out and we'll look into this for you.
Finally, our monthly price is indeed based on 28 days, or 672 hours worth of charges as per the mention on our pricing page at https://upcloud.com/pricing/. This means that if you have a server running for an entire month, you are not charged for the remaining days after the 28th. This is so that there is a uniform charge for each month, even though our charges are done hourly. Rest assured that we're not "short changing" anyone and you are not paying for more than you actually receive.
If you have any questions about any part of this response, or any of our services or terms, please do reach out to us at any time as we'd be happy to help.
Kind Regards,
UpCloud Support