Refund needed asap...

Hi,

I had registered to Prezi in order to prepare only one presentation. I had planned to use 1-month trial option but today I am charged without an earlier notice. I am not able to pay 165$ next month, impossible... How do I refund my money? I don't want a premium account, I don't even need it...

Could you please email me at melisozgenc89@gmail.com?

Thanks,

Melis