Google adsense payment issues.

My first payment was issued in 24 Nov-2010 and I received my check from Google to the address given in account information.I was very happy to receive the check.

My second payment was issued in 26 Apr-2011. I waited for 3 months but my check did not arrive. So in 29 Jul-2011 I requested for stopping the check that was issued and so my earnings were credited back. I was not sure why i did not receive the check.

Again a new payment was issued in 23 Aug-2011, but I have not received the check yet. It seems there is some issue. I don't know whom to contact. Posted this question in adsense help forums, but no answers from them either. Any advices..... ?