Is there a way to buy bitcoin immediately? I want to use PHP to write a script to buy bitcoins and my bitcoin balance will be updated immediately (i'm NOT in US).

For example, I use my credit cart to purchase bitcoins. less than 1 min later, I can see my new bitcoins in my address.

As I know, normally, it will take few hours / days to get bitcoin from some bitcoin sellers. It is not safe to get bitcoin immediately because banks allow charge back.

So is there a safe, automatic and immediate way to get / buy bitcoins?
Coinbase offers instant buys, you need to enter your credit card info and go through the verification process, but it takes less than a minute to update my balance.  The max amount for instant buy/sell is 1000usd/day.