Yes, if you win you will be refunded. It used to be the case that for appeals made during the discount period TfL would settle for 50% if they won but they don't have to and I don't know their current habit. More likely if you lose that you will have to pay the other 50% but we will find out later.
Thank you this is also my understanding which shows there is confusion on here and generally bad advice
From this appeal and there are many on tribunal (Case reference 2210379431) - Therefore the advice should be to always pay and then get the money back
The Enforcement Authority has informed me that they will not contest your appeal against the Penalty Charge Notice(s) mentioned above.
The Chief Adjudicator has therefore allowed your appeal without considering your evidence or any details of the case. You are not liable for any further charge(s) and, where appropriate, any amounts already paid will be refunded by the Enforcement Authority.