Barking & Dagenham, 50U-prohibited turn on Dagenham Heathway

I received a PCN via post for performing a prohibited turn (no U-turn) on Dagenham Heathway. I parked in the bay  right next to the snack bar shop (Street view link in google maps) I had come from the direction of Parsloes Ave so I performed a U turn to head back in that direction. In all honestly I didn't see the signs which appear on google maps as it was a busy Sunday afternoon loads of pedestrians trying to cross as I approached to park. In my opinion I didn't perform a U-turn I just turned to go back in the direction I came in. I would have had to wait for the on coming traffic to stop to leave the position I had parked in.

What approach should I take to challenge this? I do think the signage is poor and I would like to hear the views of those on the technicalities of this PCN and any advise

VRN
B19MHK
PCN BZ81107430


Copy of PCN

Thank you.

You can see the no U-turn sign and this is essentially what you breached even by parking on opposite side. I don't think you have a defence. And you can see why turning there is not a great thing.

May be a PCN issue if anyone spots anything.