I'm unsure why the page is continuously growing. This is an issue with Facebook's "Auto-grow" method where sometimes it can't detect the proper size of the page and keeps thinking that it needs to be bigger.
As for the width of the page, that's caused by your template itself from this style in the mobile.css file:
@media screen and (max-width: 524px)
.container {
width: 292px !important;
}
I'd recommend fixing that style and disabling the auto-resizing feature. That should at least get things working for you and, if necessary we can try to help investigate the resizing issue.
Thanks,
Alex