wouldn't = refused to
There are many uses of would in English, Pablo. In your example, wouldn't means refused to:
If you use wouldn't in this way, it is softer in tone and sounds more natural than saying refused to.
I could see she was crying but she wouldn't tell me what was wrong.
I invited her to my house but she wouldn't come.
would = insisted on
The converse of wouldn't in this sense is when would indicates that someone insisted on doing something.
We can use would like this when we are being critical of someone's past actions or behaviour. Note that it has to carry strong word stress when it is used in this way.
You WOULD go and tell her about the barbeque, wouldn't you? You know I didn't want her to know about it.
She said you were unhelpful? Well, she WOULD say that, wouldn't she?
won't / will
In a similar way, will can be used to talk about insistence when it relates to present situations:
Note that this is one of the few occasions when will is used in the if-clause in conditional sentences.
If you WILL eat so much, it's not surprising that you're fat.
If you WILL decline the Invitation to Muriel's wedding, there's nothing I can do to stop you.
Like wouldn't for past situations, won't can be used to talk about refusal when it relates to present situations:
Note that shan't can be used in the first person as an alternative to won't in this sense:
I can't get these pictures to download. I keep clicking on this icon, but they won't download.
It's no good trying to persuade him. He won't go and that's that.
She's invited me many times. But I shan't go.
She's invited me many times, but I won't go to her wedding.
We can also use wish with would and other modal verbs to express refusal combined with regret. Note that although we use past modal forms, the reference is to the present and future, here, not to the past:
Note that to express regret about something which happened in the past, we can use wish with could have + past participle:
I wish it would stop raining, but it just carries on. It's been raining for days.
Don't you wish this holiday might last forever? We've been having such a marvellous time!
I wish I could give up smoking, but I can't.
I wish those two would shut up. They've been arguing like that for hours.
Everybody wishes he would stay away from June, but he won't.
I wish we could have seen the match live, but we just couldn't get tickets.
I wish my dad could have been here to see me play, but he couldn't leave my mum.