In case you did use 3 times a wrong PIN code you will have to use the PUK code to deblock 

PIN and PUK codes are present in your MyProximus account

Otherwise you will have to wait for a reaction of Proximus collaborateurs on this public forum 

If not yet done do indiccate your customer number and phone number in your forum login profile (modify & save); there the private info involved only will be visible for Proximus collaborators

It’s not blocked in that way I can get into my sim, but all incoming and outgoing calls are blocked. 

Hi @Lenise could you fill in your profile with the mobile number which no longer works please ?

Hi David I did add it. 

@Lenise send or receive sms is possible ?

Sms is working but phone calls not yet.

@David W  the sms is working now. But phone calls not yet.

Hello @Lenise  , your device is classified as “lost or stolen” and it’s blocked by a specific Operator

We’ll check which one and we’ll keep you informed

Hi Again @Lenise   Your device is blocked By Vodacom ZA. So to unlock it you have to contact Vodacom in South Africa. We cannot do anything for that.