Received a Cease and Desist Letter from a Job Recruiter's (Consultancy) attorney (May 2015)

Hi, It was regarding an consulting job they had approached me for, with their Client in NYC.This was in Oct 2011. I just remember speaking to someone from this consultancy and signing/sending a Non-compete agreement which stated I could not join the Client directly or thru a third party upto a year etc. I never actually interviewed with the client for this position nor heard anything back from the recruiter. I had no idea of wat the project was or any other details. 8 months later I was approached by a different consultancy with a project at the same Client, which I interviewed and got thru. I worked there for around 2 years. Now the previous consulting firm, after 4 yrs, has sent me a cease and desist letter stating that I was in breach of contract as I had joined their client thru TP for the same project and are claiming damages or threatening legal action. Pls help !