I was driving along a road I was unfamiliar with and was (stupidly) relying on the speed limit on my satnav, which gave it as 40mph. A police officer zapped me from the other side of the road and I smugly thought 'well, I'm alright there' before driving past a brand-spanking-new 30 sign.I've received a NIP for the offence which states I was doing 38 in a 30 limit, in XXXX Road. Not know the area I drove that was again and found that the road stated in the NIP is wrong, it changes it's name twice before it gets to the bit where I was zapped.Should I just pay up and accept the points or challenge it?