Hi @Michal28, welcome on our board. 

I'm glad to help. Are you able to receive calls? Also, are you getting an error message when trying to call someone? 

Thank you Alex,

Yes, I can receive calls/texts from other countries. When I try to call there's no error message, just a quick sound. 

Hmm,. Let me check this for you. Would you please fill in your KPN profile and let me know when it's done? 

Also, do you have the country number/prefix when calling? For The Netherlands for example: 0031612345678.

I filled the KPN profile. And yes, I am using country codes when calling/texting. 

I called support, they suggested resetting. Still no Luck.

I have Iphone 13, I've reset Network settings, I turned Airplane mode On/Off, the roaming is turned ON. I also tried on an older Iphone and it still doesn't work. At the same time an international sim card (from Poland) works normally, it actually connects to KPN network.  

One more detail, when I was in Belgium a week ago, I was able to text a Belgian number at least once. Now that I'm in Netherlands I cant text to it anymore. 

Would you please try this again in about 10 minutes? 

I got messages from KPN that my settings are being changed. However, the problem persists .. I reset it, turned airplane mode on/off as before .. I still get the busy signal when calling abroad and can't text

This is so weird. Do you by any chance have a KPN shop around? Another option is to order a new simcard with the same number and credit. You can order a new here by entering your phone number en sim number. This will cost you € 5.- and will be paid from your credit. I can reimborse this amount. 

Yes, let's order a new SIM card then. Where should I enter the details?

I'm sorry, I forgot the link. You can exchange the prepaid simkaart by clicking on the link. I also added € 5.- credit to your number. Let's hope this will solve the problem. 

Thank you Alex!