Is it permissible for one in اعتکاف to use the phone to attend to the needs of Muslims?

It is permissible for the one performing اعتکاف (i'tikaf) to use the phone to attend to the needs of Muslims while inside the mosque, but he should not leave the mosque for this purpose. If a person is responsible for attending to the needs of Muslims, he should not perform i'tikaf, because attending to the needs of Muslims is more important than i'tikaf, as it involves a benefit that extends to others, which is better than a benefit confined to oneself, unless the confined benefit is one of the obligations of Islam.