Anybody else in the house that has access to your nowtv playback devices that could have accidentally purchased the day sports pass ?
Would recommend adding a payment pin to your account by going to My Account > Settings & Pin's on here.
Also would suggest changing your nowtv password.
When you go to Devices on here do all the devices on the list match ?
Then jump over to live chat, explain to them whats happend and see if they can credit you back the cost of the day sports pass and see if they can offer you more advice of making your account secure.
Link here to live chat.
Did you sell or give away a NowTV device without first deleting its contents, including your account details?