I can't send messages to short numbers anymore, like to enter a competition or get credit balance. I contacted my provider (Vodafone) many times & have all permissions etc set as should be. I even got a new sim but this didn't help. I don't get an error saying the message wasn't sent, I just don't get the reply I should. If I try enter a competition I don't get a message saying I'm entered & I'm not charged. If I message looking for credit balance I get no reply. So frustrating. What's the issue