Impossible to call or send a SMS

Hi,
I bought a prepaid card on the 28/10/2017. In the begining, it worked fine but since 1 or 2 weeks, I cannot call or send SMS with this SIM.
Of course, I still have money charged (>8€). I tried to put this SIM in another phone just it case if the problem comes from the phone but still nothing.
I tried with Nexus 5, Galaxy J5 2017 and an old GT-E1200 but still the same problem.
It seems that it can connect to the network but after there is a problem that prevents me to call or send a SMS.

What can we do except to move to another carrier?

Thanks