How can I get a refund for MuseScore Pro?

I started the trial period, and then it finished every time I was on MuseScore a kind a popup appeared asking me credit card, I entered my credit card because I was thinking it was just to register, but no, I was billed in $49,00. I really enjoy MuseScore, but in my reality in my country that 1 USD = 4 BRL I can't pay for it, I intended to use just the trial time, but I couldn't go in setting without typing my credit card number. I emailed the support early yesterday but they didn't answer me yet. What do I do?? I couldn't sleep last night thinking and how I will pay it, I really can!'t!