You can try a plugin like wp-optimize, but if the page is still stuck, it sounds like your database is in a strange state for that page.
You'll need to find out the name of your WordPress database by logging in to your site host and then opening up phpmyAdmin.
Click on the '+' next to the database name to expand the tables. If you only have one instance of WordPress installed, when you find the right database, you'll see a table named 'posts'. For security, sometimes some random characters are added to it, so it will look like 'sdfJEdssposts' instead of just 'posts'.
Now click on the 'SQL' tab on the top of the right hand pane in phpmyAdmin. Inside the box, paste in the following SQL query:
select * from <posts_table_name> where post_title='<permalink>' and post_type='page'
<posts_table_name> type in whatever the table with the 'posts' suffix is named.
<permalink>, use the name of the page whose permalink keeps getting the -2 added to it. Don't use the entire url, just the page name. For example, for
http://www.example.com/pagename, you would only use
For SQL, keep the single quotes but don't use the angle brackets.
It should bring back a single row that has the page information with an option to delete that row. Click on 'Delete' and that page should be cleaned out of your database for good.