When you sign up your child to Dynamos Cricket and select their t-shirt, you will be sent a confirmation email containing the details of your order. If you search your inbox and junk/spam folders for mail@clubspark.co.uk, you should be able to locate the email.
Alternatively, you can check with your bank to see when the payment went out to establish the date you received your confirmation email. Otherwise, the Dynamos Cricket Help Desk will be able to assist, contact the Help Desk by emailing dynamoscricket@ecb.co.uk and we can look into this for you.