Did Obama give help to Ambassador in Libya?

First, not all of the facts are in about what happened in Libya, but it is a myth (spread mainly by Fox News and some of the president's political opponents) that the president refused to help his ambassador. He chose this ambassador, and by all accounts, they had an Excellent relationship. There is every reason to believe the president wanted him to be safe.

There is also no evidence that President Obama intentionally failed to protect the diplomats serving in Libya. What did happen, how the ambassador died, and what more could have been done to keep him from harm is still being investigated, both by a non-partisan commission and by the agencies that were involved, including the State Department and the CIA. It should also be noted that congress had cut the budget for protecting embassies, including the embassy in Libya. Whether this played a role is also being determined by the ongoing investigation.