This depends on how you signed up.
If you signed up through PlayStation Music your subscription is being renewed through your SEN account wallet. This means that your subscription payments will be displayed on your credit or debit card statements as payments to PSN or PlayStation Network.
You will also find a record of subscription renewals in your SEN Transaction History, through which you can also cancel your subscription renewal up to 24 hours before the billing date.
If you signed up for your account directly through Spotify, check Spotify support to find out how to cancel your subscription.