whom should I contact for my MacBook air problem? Any Phone number?

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Keep in mind, free Apple contact for software issues is limited to 90 days. Hardware issues is 1 year. A purchase of AppleCare warranty extends the time offered on both on the support tab. This forum offers moderated access to end users who can help each other on a wide variety of problems. I'm actually an Apple Certified Tech, though no longer working under an Apple Authorized Service Provider. So you can get good knowledge here even out of warranty.

KiritSuthar wrote:

whom should I contact for my MacBook air problem?

Any Phone number?

You could use the "Support" link located at the bottom left of this page.

Or, you could describe your problem and we users could try to help you.