Hi @Anonymous User
The week & day sports passes do not auto renew, so you won't be able to see a cancel option under My Account > Passes & Vouchers whilst logged in on here.
For a refund, pop over to live chat and explain to them what's happened (which happens quite a lot with little ones if you haven't added a Payment Pin to your account).
To reach live chat open the link below, then click on the small green arrow directly underneath How to Get in Touch to reveal the live chat button.
Then once you have been hopefully sorted out by live chat, then go to My Account > Settings & Pins on here and add a Payment Pin to your account to prevent this happening again in the future.