Telecom always sends short messages these days saying that 20m will upgrade 50M broadband for free. Is it really free?

Of course it can't be free. It will use the mobile phone to bind the package into your pocket. If it is not necessary, there is no need to upgrade.

If it's free, go directly to 50 m. I don't think anyone will object. Why should we send text messages to customers? Just think about it, don't you think?