You bought webhosting from a company offering ''unlimited webspace'' and ''unlimited bandwidth''. Believe me those webhosts can't offer you that.. there is a cap somewhere although they won't tell you until you reach it and than they'll suspend your account.

For 4.95 USD I would expect that using only 11GB bandwidth is no problem. Same for disk space usage.

What you need to do is try one more time to get in contact, give them 24 hours to respond and if they still don't help you create a Paypal dispute if that's your payment method.