Summer school not answering my e-mail I've been accepted to Scuola Matematica Interuniversitaria, Perugia, a summer school for graduate students in mathematics (received the acceptance email on the 5th of July).
I've sent them an email (on the 5th of July) asking about the financial details and the arrival date in order to be able to give my home university an estimate of the costs (they are partiality funding me).
I have received no answer from them. I cannot send the enrolment fee and buy my ticket until I am sure I will receive enough financial aid from my home university to afford attending the summer school and my home university can't tell me if they will be able to help if they don't know the costs.
I've asked the summer school about the costs immediately after sending my application and I've been answered that my e-mail has been forwarded to someone who can answer my questions but they never did. After getting accepted I asked again and now I am waiting.
Is there anything else I could do?

I want to add that I would really like to attend the summer school. I understand that is a good learning opportunity for graduate students (I am a second year undergraduate student).
No answer after 2 days in not unusual. Dont forget that they most likely don't have all the staff working full time on the summer school and questions like financial compensation may have to go by the responsible in the inviting institution, and not the company paid for handling the practical issues