Ionic 2 Contacts save() problem

Ionic Framework ionic-v3
1

Trying to save contacts using the information provided at : https://ionicframework.com/docs/v2/native/contacts/.

Single contact save works well, but when it comes to save more than one, contact.save() again saves contacts to phonebook but the related promise does not return anything, just hangs.

So in my case below, Promise.all never ends, it keeps running and waiting contact.save promise to be resolved or rejected. Any help is highly appreciated.

Related code:

let promises = [];
      for (let user of this.phoneBookUsers) {
        let contact: Contact = Contacts.create();
        contact.name = new ContactName(null, user.surname, user.name);
        contact.phoneNumbers = [new ContactField('mobile', user.mobile)];
        promises.push(contact.save());
      }

Promise.all(promises)
          .then(t => {
              console.log("done");
            },
            error => {
              console.log("error");
            })
          .catch(error => {
             console.log("error");
          });