Free Traffic Legal Advice

I have recently received 4 parking fines for parking in a SIP car park. I attempted to pay but mistakenly (due to bad reception in the area) paid for a different car park via the PayByPhone app due to a car park on the same street coming up. I have appealed the fines, showing evidence I paid in good faith (although for the wrong car park). However, the appeal has been rejected. Is it worth taking this further or should I just pay the £60 each instead of risking having to pay £100