I cant change size of my logo

Please i need help , i am trying to change modify the logo and uploaded the new log (600px width-150px height) but it appears smaller like the default size and i modified in template.css but also no way , here below the code:

#component_wrap { border:1px solid #E5E5E5; padding:11px; }
/* logo */

h1.logo { background:transparent url('../images/logo_bg.png') no-repeat 0 0; border-top: 8px solid #1d1d1d; float:left; height:150px; padding:0; width:600px; }
h1.logo a { background:transparent url('../images/logo.png') no-repeat 0 0; display:block; height:150px; margin:0; text-indent:-999em; width: 600px; }
/*TODO*/

div.logo { background:transparent url('../images/logo_bg.png') repeat-x 0 0; height:150px; border-top: 8px solid #1d1d1d; width: 600px; float:left; }
div.logo h1 { font-size:27px; line-height:32px; font-family:Georgia, serif; font-weight:normal; margin:10px 10px 4px 10px; color:#fff; }
div.logo h1 a { color:#fff!important; font-size:27px!important; text-decoration:none!important; }
div.logo p { font-size:11px; font-family:Verdana, sans-serif; line-height:12px; color:#a8a592; margin-left:10px; text-transform:uppercase; }

I hope u help , Thanks

Hi
Can you give us url to your site ?