How to remove users from SharePoint groups through code

 

You can create a variable to store the current user(who created) the survey item.

then create a method 

public void removeuser(string groupName, string userLoginName)
{
    string strUrl = "http://mysite:5050/";
    using (SPSite site = new SPSite(strUrl))
    {
        using (SPWeb web = site.OpenWeb())
        {
            try
            {
                web.AllowUnsafeUpdates = true;
                SPUser spUser = web.AllUsers[userLoginName];
                {
                    SPGroup spGroup = web.Groups[groupName];
                    if (spGroup != null)
                    spGroup.RemoveUser(spUser);
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                web.AllowUnsafeUpdates = false;
            }
        }
    }
}

 

call this method and pass the group name & "variable" created earlier.

Note :Replace "http://mysite:5050/" with your site URL