If you actually clicked the "transmit now" link, you have filed your return, nothing can be changed. If your information was incorrect, you will have to wait until March to file an amended return. You can't cancel any fees or agreements after you transmit.
If you did not transmit, these instructions may allow you to change your options and payment method.
https://ttlc.intuit.com/community/downgrading/help/how-do-i-remove-premium-services/00/26266