Awful mess in my agenda: Every appointements duplicated

[GD61]

Help !

this morning, I ran a sync between MS Outlook - MyPhoneExplorer- and my SAMSUNG Galaxy S7: on the phone, every appointment is repeated twice, side by side (For my job, I must keep the history of every appointment on several years.)

How can I cleanup my Samsung phone ?
Thanks and regards

[GD61]

Hi,
Today, when I want to sync my Contacts, MyPhoneExplorer tells me my Contacts view on the phone is empty so it prepare to create 550 contacts. It want to duplicate all my Contacts as it already duplicated all my "rendez-vous" in the agenda.

How to correct these bugs?

If there is no solution; could you advise my another software which do the same sync between MS Outlook and my SAMSUNG Galaxy S7 without these bugs?
Thanks