Translation of payment confirmations mails, and showing correct amount

How to change content in client email "Payment Confirmation for <<service>>"?

When system send me an email to notify me that an invoice has been paid, it is all in english (where/how can I translate?)

Also; The sender ID on email to me about client payment has sender ID: "Agency Handy (mailto:support@agencyhandy.com)>"
And also it is showing logo for Agency Handy, instead of my logo.
I would like the sender ID to be "Hotspot Søvang (mailto:hotspotsovang@safi.dk)" as it is in most mails sent to clients?).

Also, in the generated notification it says "Amount Paid: "0", even the invoice was "6". It looks like it does not catch the unique amount correct.