At last I was able to open a bank account. Until then I hadn’t been able to because I didn’t have a job contract. And without a bank account I couldn’t obtain a Carte Vitale (health insurance card).
Today, having my residence permit application receipt, I have: found a job, opened a bank account, asked for and received my Carte Vitale. And now, with these supporting documents I will be able to assert my right to renew my residence permit.