I placed the Order and pay the by Visa card, but I never receive the item.

Please, see: https://musescore.org/en/faq#faq-314712

Duplicate of https://musescore.org/en/node/345909, but a tiny bit clearer.

What item? Here on musescore.org nothing is sold or sent, everything is free.

But see https://musescore.org/en/faq#faq-20657 and maybe https://musescore.org/en/faq#faq-314712