Wowow! In this position my first step would be to determine if there's any legal basis for disputing the charge (an informal conversation with a lawyer or even just someone who's been through a similar experience is a fine start). Even when a billing change is disclosed in advance and the customer actually uses the bandwidth, massive spikes in metered pricing are a tricky area and have attracted the attention of regu…
Let's calm down.
The first step is to pay the bill, set up better infrastructure monitoring on your end, so you don't act surprised that you are consuming 7000% more resources than third party service is reporting.
Then, if you want to burn some money, you can file a petition and tell the court that you deserve to get free service because you did not know that you have been going over the reported data by 50%, I mean 7000% for... two years.