Free Traffic Legal Advice

I received two PCNs yesterday for parking on a single yellow line on Durban Road (N15, there's a few Durban Road's about) during restricted hours.  The alleged restriction is that the yellow line prohibits parking during event days at the nearby London (West Ham United) Stadium from 8am - 9pm, as well as 9-6 on weekdays.  My issue is that there are no nearby signs informing road users of this restriction.  The opposite side of the road has marked boxes for resident permit holders (which have the same weekday/matchday restriction) but nothing for the single yellow line.  I think this is because the area is an RPZ and the signs are located on the entrance and exit to the zone.  But the nearest one of these is 250m away and across three junctions.  Frankly, I didn't see this when I drove into the area a few days ago and since there were no signs adjacent to the single yellow lines decided it seemed the best bet.  I've just moved into the area and am unable to get a permit because I'm borrowing my Dad's car for a couple of weeks and it's not registered to this address.  I desperately need the car for the next few weeks but I have absolutely nowhere to park it legally nearby (even if I was prepared to pay!) as everything is either this single yellow line, permit holders box or private (CPM) parking for developments.  I honestly just feel so frustrated that I have nowhere to park it so some advice would be much appreciated.  I don't hold out much hope of getting the PCNs overturned but it would be amazing to get some advice on what to do next.

location of parking:
https://maps.app.goo.gl/dvocCEzhxJWbz9kZ9

location of nearest sign (I went out on foot to find this today):
https://maps.app.goo.gl/NcbTBqNLHwojraZs5



Many thanks
Luke

I had nowhere to move it too!  I'd hoped that after getting one they wouldn't give out another...naive I know.