Learn Italian: Devo bloccare la chiamata, non ce la faccio più. - I have to block the call, I can't take it anymore.

It comes from the verb farcela, which means to manage, to succeed, or in this context, to take it. It is made of the verb fare (to do) plus the pronouns ci and la. When conjugated for the I form, fare becomes faccio, giving us ce la faccio (I can manage it or I can take it).

Why is it ce instead of ci in ce la faccio?

In Italian, when the pronoun ci is immediately followed by another pronoun starting with an L or an N (like la, lo, li, le, or ne), the ci changes its vowel and becomes ce. This makes it flow better when speaking. So, ci plus la becomes ce la.

How does the negative non ... più work in this sentence?

The phrase non ... più means not anymore or no longer. In Italian, you place non before the verb phrase and più immediately after it. Since the pronouns ce la belong to the verb, they go inside this sandwich, creating non ce la faccio più (I cannot take it anymore).

Why use farcela here instead of just saying ?