I have the exact same problem and also have reported it here in the forum, hopefully someone will look into it because it’s so annoying! 

Hello, @Lipi Jain and @sofiavazsousa.

Welcome to the NOS Forum and thank you for reaching out to us. 

We apologize for the situation you describe. Please, allow us to help you.

We will work to resolve the situation immediately. Just send us a private message to the @Fórum profile, with your NOS Costumer Number, please. 

Thank you for your understanding

Thank you Joao, I have sent a message, hopefully they can fix it :) 

We've received your private message and will reply as soon as possible, @Lipi Jain.

Thank you

It has now been 5 days of getting 300+ messages every single day!!  Can you please help. My private messages are getting one reply every 24 hours asking for more information. I even called customer service today for 1 hour, got told I would get a call back and no answer. 

Now my data service is not working even though I have available tariff. 

@sofiavazsousa  did your problem get solved? any helpful tips? 

I’ve been now around 12h without receiving those annoying messages, the only thing I think helped was turning off the voicemail service - you can do it in your settings on nos.pt or ask the customer service to do it for you, hope it works! 

Hello,

Thank you for your message @Lipi Jain. We’re sorry about the delay.

We’ve received your private message and will reply to it as soon as possible.

Thank you