iphone Xs Max with 2 sim - Cannot change my old tel number

Greetings, dmitry47.

Congratulations on your new iPhone XS Max. I see that you're having an issue changing the primary phone number of your Apple ID in order to use Messages and FaceTime on your new device. You're using your old phone number on a different phone and a different Apple ID, but you can't change the phone number of your Apple ID on your new phone. I'm happy to help.

Add or remove your phone number in Messages or FaceTime -- First, starting with Messages, follow the steps in both applications to remove your phone number. Then, starting with Messages again, add your new number to both.

Remove your phone number

If you don't want calls or messages for your iPhone on your iPad, iPod touch, or Mac, you can remove your phone number. There are two ways to do this:

• On your iPhone, go to Settings > Messages > Send & Receive. Select your Apple ID and tap Sign Out. Then go to Settings > FaceTime, select your Apple ID and tap Sign Out.
• If the phone number that you want to remove belongs to an iPhone that you can't access, change your Apple ID password. This removes all phone numbers from your iPad, iPod touch, and Mac. Calls or messages for the removed numbers won't appear on those devices anymore.

And

Set up your phone number

On your iPhone:

1. Go to Settings > Messages and make sure that iMessage is on. You might need to wait a moment for it to activate.
2. Tap Send & Receive. If you see “Use your Apple ID for iMessage,” tap it and sign in with the same Apple ID that you use on your Mac, iPad, and iPod touch.
3. In the "You can receive iMessages" section, make sure that your phone number and Apple ID are selected.
4. Go to Settings > FaceTime and make sure that your phone number and Apple ID are selected in the "You can be reached at" section.

Apple - Support - Product Selection — If those are the steps you used previously, or the steps above didn't work, it's time to contact Apple Support. After selecting this link, choose Apple ID > iCloud, FaceTime & Messages, then select the method you'd like to contact them with.

Take care!

Thank you for trying those steps, dmitry47. It's appreciated. Since you're unable to reach Apple support using a web browse, here is a list of phone numbers you can use.

Contact Apple for support and service -- Select the region you're in, locate the phone number, then give them a call.

Cheers!