Support

You can't see the number of credits per user except when you are replying to a client. The reason is that we don't keep a full double entry ledger of credits (otherwise credits could never expire, even if a refund on their purchase is issued). The problem with this flexible approach is that determining the amount of credits per user requires three queries and quite some time. For one client it's not much time. If you want to display a list of credits per client or, much worse, query the clients with less than X credits it is prohibitively expensive in CPU time required.

Regarding variable amount of credits per ticket, it is already implemented. You can set a custom number of credits in your reply. You can also have a different amount of credits for each ticket based on category, urgency and public/private status. You cannot modify this information afterwards and I think that's the only fair thing to do to your client. When they file a ticket they know they are charged X credits. If you go ahead and change that to 2X credits their trust to you is abolished, don't you think?

I tried to see the credit but they sounds to be available only on the back end reply, my technicians don't have access, is there a way for me to show them on the front end for our technicians ? 

Quite the opposite. The custom credits per reply are available in the front-end replies. Look below the big reply area. Note: you need to have of course enabled the credits system in the component's options.

I try to show the credit module but it is the credit of the logged user, that make sense of course!

Yes, it's the same reason I explained in my previous post. Calculating credits for a single user is a bit slow but still practical.