The normal definition of a "blocked" phone call is for it to go directly to voicemail without ringing the phone. If you later unblock the number, that only affects new calls, not the old ones.
What happens with blocked/rejected SMS messages depends on your SMS app. The standard behavior for blocked numbers is to receive the message silently and discard it. Some apps will put the message into a "spam" folder instead of discarding it. Either way, now that the phone received the message (saved or not), there is no "receive again".