Look at this sentence:

• Janet and John painted their flat.
• This tells us that Janet and John were the painters; they painted their flat.

Now look at this sentence with have something done:

• Jane and Paul had their flat painted.
• This tells us that Jane and Paul wanted their flat painted, and that someone painted it for them.

Here are some more examples:

• Sheila is going to cut her hair.
• Sheila is going to have her hair cut. (= Someone is going to cut it for her.)

• She washes her car every Sunday.
• She has her car washed every Sunday. (= Someone washes her car for her.)

• I must clean my suit this week.
• I must have my suit cleaned this week. (= I must pay somebody to clean it for me.)

• I’ll mend that broken light.
• I’ll have that broken light mended. (= Someone will mend the broken light for me.)

We sometimes use get instead of have:

• Sheila is going to get her hair cut.
• She gets her car washed every Sunday.
• I must get my suit cleaned this week.
• I’ll get that broken light mended.

Now look at this example:

• Susan is very cross. She had her bike stolen.

Here, we use have something done to talk about something that happens to somebody, usually something unpleasant. Here is another example:

• The band had two concerts cancelled because of poor ticket sales.