No it's not compulsory to have an entertainment pass with your Hayu pass, where all passes are separate and can be purchased & used standalone.
Is there anybody else who has access to nowtv such has little ones for example who may have accidentally bought the entertainment pass through your nowtv playback devices ?
Would always recommend adding a payment pin to your account to avoid anybody else in the house buying passes without the account holders knowledge or permission.
You can add a payment pin to your account by going to My Account (person symbol if using a mobile) and from the drop down menu option select "Settings & Pin's".
With regards to the unauthorised payment taken of £7.99 for the entertainment pass, then jump over to live chat for further assistance for seeking a refund and whilst online ask them to cancel your entertainment pass.
Link here to live chat or alternatively drop them a message.