Jamming - Feature Reqeust: Playlist Edit

Has anyone successfully implemented the ability to fetch a users playlist and use the Spotify Change a Playlist’s Details PUT request?

I am successfully retrieving playlist details.

However, I am having an issue of the PUT request being sent (to change the playlist title), but returning a 403 Forbidden message, despite re-issuing an access-token with the correct permissions granted on login.
This is the code, if some one could look at it with fresh eyes -

 savePlaylist(playlistName, uriArray, userId,  playlistId) {

        if (!playlistName || !uriArray) {
          return;
        }

        const accessToken = Spotify.getAccessToken();
        const headers = {
            Authorization: `Bearer ${accessToken}`
        };

        //Check for existing playlist id. If True, change playlist details (title).
        if (playlistId) {
            console.log(userId);
            console.log(playlistId);
            return fetch(`https://api.spotify.com/v1/playlists/${playlistId}`, {
                headers: headers,
                method: 'PUT',
                body: JSON.stringify( {name: playlistName })
            });
        }

        return fetch(`https://api.spotify.com/v1/users/${userId}/playlists`, {
            headers: headers,
            method: 'POST',
            body: JSON.stringify( {name: playlistName })
        })
        .then(response => response.json())
        .then(jsonResponse => {
            const playlistId = jsonResponse.id;

            return fetch(`https://api.spotify.com/v1/users/${userId}/playlists/${playlistId}/tracks`, {
                headers: headers,
                method: 'POST',
                body: JSON.stringify({ uris: uriArray })
            });
        });
    },

Thanks in advanced!