Perhaps it hasn't been spelled out clearly enough for the angry-by-default, inflated-sense-of-personal-entitlement kiddywinks here;
When you chose to buy this game, you paid for the SP content. The Online MP content was provided as an extra by R*. Whatever they choose to add or not add is at their discretion. If you don't enjoy the online portion of the game, don't play it. If you think R* have misled or are misleading you, consider taking legal action against them.
Now drink your cocoa and get to bed.