Well it is rare to get a council employee who is sympathetic!
Being totally honest, if it was me I would think the time spent faffing about and trying to appeal is worth more than the £35, so I would just pay it.
Added to the fact that parking on zig zags will get you 3 penalty points (which you seem to have gotten away with!) I would just pay it and be done, rather than risk appealing etc and maybe them taking a closer look.
But that's just me. You may, quite rightly, think that there's the principle of the thing and that common sense should prevail, in which case, more power to your elbow!