Sometimes people we like very much abandon us for their own selfish pursuits, taking vacations or business trips without caring if we will feel lonely. In which case you should first pawn their valuables to teach them a lesson. And because they haven't adequately prioritized your needs for entertainment and diversion, you should start guilt-tripping them right away. When they know how much they have wronged you they will soon return home in apologetic tears. How long it takes you to forgive them for abandoning you is up to you. So send them a Missing You Card to get the ball rolling now.