A declined request does not become a connection. There is no Spark charge to reverse, because connection requests do not spend Sparks.
Cofelt does not send a separate rejection notification. Check your sent requests for current status. A pending request means the other person has not accepted it; silence is not permission to contact them repeatedly.
Respect their choice. Do not use another account or contact route to get around a decline or block. You can continue using your own Network without needing an explanation from them.