Permalinks have number suffixes

I am using WordPress, and I have created a contact page titled ‘Contact’.

Now everytime I delete the page and add it again, it adds a number suffix to it:

http://myurl/ik/contact-2/, http://myurl/ik/contact-3/ etc

So I believe there must be already existing names in the DB that occupies the titles, so I cannot overwrite them…

How can I remove page names for pages that has been deleted?

I only want the permalink to show:

http://myurl/ik/contact/

but it does not allow it in the admin panel.