I Am Pissed Off

My son from my first marriage who was adopted when he was young found me on fb the beginning of last year and we drove up to see them nearly every week in the summer .I invited him down in the winter as it was becoming a strain on my health even offered to pay the fair for him ,his wife and 2 kids. Ever since then I have not seen him .Its been one excuse after another .We were meant to be meeting them Saturday and geuss what ,one of the kids was apparently sick ,but not too sick to go and see his adopted parents which he plastered all over facebook .My wife and I bought the kids birthday presents and xmas presents for all four of them we didn't even get a card in return .I just wonder why he bothered to get in contact as it all seems one sided and he seems unwilling to make the effort to come and see us .