At the beginning of "Ex Libris" (Series 2) Piper tries to get Phoebe to sign their Dad's birthday card, and Phoebe refuses, saying

"Why? He never sends me any."

Then Piper says "She's right. He doesn't, to any of us, so why do I keep trying?"

Yet in the Series 1 episode "Thanks for not morphing" Prue is talking about how much she hates Dad and how he abandoned her etc. and Phoebe says "But he sent us birthday cards?"

Well, did he or didn't he?