SVN not working ( tried several times but not working)

Hello, support,
I tried to upload a new version of my WordPress theme via the SVN method but each time it shows an error to me ( Access to ‘/!svn/me’ forbidden ). it says that I’m using the wrong username and password but with that same username and password I tried to make any changes in my plugins file via SVN then it works. how is this possible that it works for plugins but not for themes.
Please help me out asap. I really need to upload my theme’s new version asap.

Thank you
Regards