You would have ended your contract @JoshCrane , otherwise the contract will roll over on a month to month basis until you cancel. The best way to achieve this is by using a PAC or STAC code, this way the contract will immediately end and providing you are out of contract there will be no further charges.
It is usual to get billed after cancellation, this is due to Vodafone billing a month in advance, providing you don't cancel the direct debit anything overpaid will be credited straight back to your bank account. Vodafone will send two further bills, one for the month you have cancelled and the final 0.00 bill as your confirmation there is nothing further owing. There is further information on the things to know before you leave here: Cancellation
If you still need clarification drop the Social Team a message through social channels here: Contact Us
