When I worked as engineer, I was getting them quite often, because sometime you just HAVE to park somewhere and in that particular case it's not a main road, so nothing awful could happened if you parked there for some time
Just appeal against the decision, it won't cost you absolutely nothing. Very easy process, just find council's e-mail(department of transport) and write them, why you're not agree, saying, that you were in a rush and haven't noticed the yellow lines, as they definately need to be repainted.And add, that you'd never park your vehicle there if you knew about the lines, and that if council will charge you then you will be very disappointed, as they take money but do NOT spend them on new road marks, so where do the money go then...
For me it worked in 50% of cases, so give it a try. But anyway, you're guilty for parking like that, especially when you have a chance to park at allowed place.