Im not able to activate my iMessage and I’m asked to contact the customer service

If you already tried (to no avail) all the steps provided in the support article that led you here, contact Apple Support directly, using this link:--> Contact Apple for support and service or make an appointment (*) and have your device inspected at an Apple Store or AASP (Apple Authorized Service Provider) among this list:--> https://locate.apple.com/choose-country-region . After checking it out, they'll give you all the available options.

Regards

Giulio

(*) You can do it:

• Online:--> Genius Bar Reservation and Apple Support Options - Apple;
• Contacting a local Apple Store or AASP among the list provided above;
• Using the "Apple Store" app, available and downloadable from AppStore.

If you can’t turn on or sign in to iMessage or FaceTime read this support article --> If you can’t turn on or sign in to iMessage or FaceTime - Apple Support

- Note the sections at the bottom about "Still not activated...?" and "Get more help."