Thanks for your enquiry.
Firstly, I'm afraid the Seller was not under a legal obligation to inform you of any such subsidence claim (morally yes, but legally no).
Unless the claim resulted from a coal mine subsidence claim, your Solicitor would not have been aware of any claim, and nor would any of his searches/enquiries revealed the same. If it was a coal mining subsidence claim, depending on when it was made, this WOULD have been revealed in the Coal Mining Report your Solicitor should have undertaken, if indeed the property is in a coal mining area.
Subject to the above, your only possible claim is against the Surveyor if you have had a full Building survey. Although I am not a Surveyor, and therefore not qualified to say for sure, there is a possibility that the Surveyor may have picked up that there had been some subsidence. You would need to speak to an independent Surveyor to get a professional opinion on this.
I hope this clarifies the legal position for you.