I would notify the couple. Its their shidduch you did, and if they are happy with the result, they should pay you. As is the case in many marraiges, they think mom and dad have taken care of everything, but indeed may have ignored one or two (vital) responsibilites. As far as the couple not calling you since engagement, chalk that up to today’s youth. But point it out to them, so they can learn from the mistake.
The parents are rats, but that’s a different story