When switching to a different subscription it is best to uninstall completely via Control Panel. Then run the MCPR cleanup tool listed under Useful Links above and reboot immediately.
Then install the new one from your new online account or the CD if that's how you bought it, as this is now a completely different subscription.
You could also try the subscription repair tool: HERE.
Our records show that you are in Tunisia so your best way of contacting support would be here, for Technical Support and if it's to do with the account/subscription Customer Service.
If you prefer French speaking then alter your country to France at the top right of those pages (or any other you prefer).
There is free telephone support but your best choice most likely would be online chat.