@justinamthor All providers have the same approach to the first bill. This will explain in detail:

https://www.koodomobile.com/en/help/charges-explained

Rest assured you are not paying extra. 

There is a partial charge from the start to the billing cycle date, and then a charge for the next full month. You can see this by looking at the dates associated with the charges. This is normal with all monthly post-paid accounts from any provider. Next month there will be a charge covering the billing date to 1 month in advance.

At some point in the future, if you cancel your account, will will receive a credit from the cancellation date to the end of the billing cycle.

Thanks for your help!