Acrobat Pro Unsuccessful activation

I have successfully paid for Adobe Acrobat PRO and received the confirmation email. When I open the desktop app and try to activate the PRO vesion a notifacation pops up stating ''Your purchase wasn't detected. If you've made your purchase, please try sign-out and sign-in again in Adobe Acrobat''. I have already tried this and even restart the PC but still nothing. 

If anyone knows how to solve it I would appreciate it. 

Thank you in advance.