(someone) has had to (do something)

You say that someone "has had to" do something when you're talking about a situation that started in the past and is still continuing now. For example:

I've had to work late every night this week.

Someone might say this on Thursday or Friday because the week hasn't ended yet. But you wouldn't say this if it's Saturday and you have the day off. In that situation, you'd say:

I had to work late every night this week.

In the example at top, the speaker says "we've had to turn away business" because the company is still very busy and might have to turn away business again.

actually (do something)

"Actually" is a word that you use when you're saying something that you think will be surprising or new information to the listeners. For example:

Wow, this is actually pretty good.

I actually did it myself.

You can use "actually" in several places in a sentence. One place is before a verb:

I actually left it at home.

Another is before an adjective:

It's actually fun.

A third is before a noun:

He's actually my brother.

turn away (business/customers/etc.)

To "turn away" business or customers means to say "no" and not serve them or sell them things. A company might "turn away business" because they already have enough customers, because it's time for a store to close, or because they have some disagreement with certain customers.

You can use "turn away" with other words as well:

turn away gifts

turn away people

turn away advertisers

When you use "it", "them", "us", etc. with "turn away", "away" comes at the end:

We had to turn them away.

business

The word "business" can have a variety of meanings. It can refer to a company, the things that a company does, or to the amount of sales that a company makes.

In the example above, "business" means customers who want to buy from the company.