Avoid using the META refresh tag. It can get your site banned.
Utilize a 301 Redirect in your htaccess file which is a Permanent Redirect.
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That makes things a little tuffer.
Change hosting providers that provide htaccess
What server are you on? In Apache use .htaccess, in ASP(.NET) use Respons.Redirect. None of them breaks the Back button.
(I realise that Respons.Redirect is not a permanent redirect, but it's still a lot better that META refresh.)