Conversion problem

Hello, our site uses two currencies. Shekel for Israel and US dollar for other countries. Respectively for Israel the cost of the course: ?49 and for other World 15$ but when I tried to pay from my country (not Israel) I received an invoice in the mail that I paid 15$ But when I went into my banking I saw that the change had withdrawn only 15 shekels! This is a very big problem that could lead to serious financial losses for my client(site owner). Please help me to figure out this issue.

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