Sorry to be blunt, (and sorry, hope you aren't offended), but what you're telling us is that you obeyed Google instructions like an automaton and ignored all the traffic signs that you passed. Is that a correct summation ?
We see so many threads on here where the OP says "I was following satnav". These are never, ever, up-to-date, even if you just did the update an hour ago, because they rely on base data that may only be updated once a year and which rely on an information feed about new restrictions. Even if up-to-date, they may not indicate restrictions that only apply on part of a day or a week.
So my first recommendation is to cease using and obeying Google without looking out carefully for signs barring access. The ones you will have passed will have been what we call "FLying Motorbike" signs, which mean " No Entry for motorvehicles", with sometimes a plate below giving days and times the no entry restriction applies. These are now very common for streets with schools on them.
Now, to your PCNs. If you make several contraventions for the same location, and only become aware of them when the first PCN arrives, then you should submit representations that you only became aware on <date> that you had commmitted contraventions at <location> and request that PCNs dated <date, date date> that occurred after the first PCN but before the date you became aware of the problem be cancelled. You would obviously offer to pay the first PCN.
In may cases, the signage indicating the restrictions are badly placed or have no advance warning, so are 'inadequate', a key requirement of Regulation 18 of The Local Authorities’ Traffic Orders (Procedure) (England and Wales) Regulations 1996. If you want to contest a PCN on this aspect, be aware that as far as councils are concerned, all their traffic signage is adequate, even perfection, so refuse all reps, so you must be prepared to forego the discount option and take them to London Tribunals for an unbiased decision.
