If I've deleted a contact from my phone, but they still show in watsapp is this because they haven't deleted me from their phonebook? Also, if messages deliver but are not read, does this mean your blocked? Or is it more likely read receipts are off or your 'muted'? I cant understand how calls are blocked but watsapp messages deliver? Thanks
The contact which you deleted from Contacts list might still appear on Whatsapp, if the Contacts list of Whatsapp isn't refreshed. However, on newer versions of Whatsapp, this happens instantly. And no, it has nothing to do with your number being saved on their Contacts list.
Coming to the scenario related to blocking, once you block a contact on Whatsapp, the message is sent from their phone but not delivered to you, in which case they get a single tick, this however stays the same even after you unblock them, i.e. you still wouldn't get their message. This is so because the message sent by them is stored on Whatsapp servers rather than being delivered to you because they were blocked. With calls too, the person who is blocked cannot get their call through to you if they are blocked.
I would like to suggest you to first search for information already present on Google before posting a question.