Mobile line not working, unable to make or receive calls/sms, how to activate?

Bonjour,
I've subscribed for La Poste Mobile on the beginning this month (April, 2021). In the client area there is an invoice, however I was not able to pay it through direct debit (it might be a problem on my bank's side), or through credit card (after making payment procession and approving transaction on my side nothing has just been happened), or at a post office itself (they said call 904 'cause we are not able to help). Two days ago my number stopped to work, I'm not able to make or receive calls/SMS, even calls to 903 is not available just awful sounds like siren. So how it suppose to be reactivated (activated) if even calls to official number 904 are not possible?
Yesterday (April 28, 2021) I paid the invoice of 10Euro at La Poste Bank with additional bank fee 5Euro. And now mobile line doesn't work.
How long it takes to reactivate my phone number and make it available for calls/SMS? Do I need to do extra steps to reactivate my line?
P.S. I've done phone restart several times, inserted SIM cart to another phone, but it didn't help. There is full network coverage and phone displays that network is available and it is connected to the network.