The response I got (which I assumed):
“Hello Daniel, The reason it charged you as soon as you made the change is because when you change the billing cycle or selected plan, the changes reset the cycle and the effects are immediate. I’ll go ahead and wipe out the $70.01 that is owed on the account, as this was simply an honest mistake. If there’s anything else I can help you with, please let me know! Thanks! Christian”
The good news is that I do not have to pay $70.01, thank you Dreahost. w00t!