reservations for Da Vinci's The Last Supper

I have tried several times over the past month to make reservations for The Last Supper over the phone using the number given in RS's Italy book, to no avail. Once I get through, I press 2 for the English-speaking operator. Then, I am placed on hold. Periodically, a brief recording in Italian comes on, which I assume is the "thank you for holding, etc" deal. After several of these brief statements, a longer recording, also in Italian, comes on. All I can make out is grazie and presto, and then the call automatically ends. I don't know why on earth they would put Italian statements on the English- speaking line. We will only be in Milan for 2 nights and one full day in early June, so I do not want to risk waiting until I can book online, which will be in about another month. Nor do I want to purchase an expensive tour in order to see The Last Supper. Has anyone else experienced this problem or know what is being said? I welcome any suggestions on how to reserve these tickets over the phone. Thank You.