iMessage and FaceTime Activation Error

Recently i bough a brand new iPhone 16 Pro max, and since i live in iran, i put my main iranian simcard from local carrier 'Irancell' in it, my imessage and facetime got instantly activated. but since my simcard itself had some issues and my network signals were annoying me, i was asked by the costumer support of my carrier to change the sim, so i changed the sim ( same number, just difference sim card ). When i inserted the new simcard into the phone, my iMessage and Facetime did not activate anymore,

i have been searching the web and forums and everywhere you name for the past few days,

People and experts suggest that this might be related to my carrier blocking international messages, i tested with another phone which has Delivery report enabled and sent a message to one of Apple's message centers ( +44 7786 205094 ) it was delivered without any problem, so the message is being sent to apple and it is getting delivered without any trouble.

i also tried

1. Factory resetting the phone!
2. Logging out from my apple ID and trying to activate i message
3. Logging in again and trying to activate..
4. changing region to somewhere other than iran
5. a bunch of other suggested methods ( Using VPN, changing Time, Location, using WIFI or changing DNS, ... )

so i want to ask you guys, if anyone else experienced such troubles with activating iMessage? i just recently switched from Android to Apple and i am regretting my decision to be honest, because Facetime and iMessage were one of the bonus points i wanted when i moved toward iPhone, but it seems like there is no costumer support from apple side for users in Iran, or there is some sort of blockage or restriction on iOS or iMessage after you deactivate it once and then try to reactivate it.

At least if anyone is able to provide me with some details about how the whole activation process works it would be so helpful and i might be able to troubleshoot it in my own and find a way for myself and other Iranians to solve issues like this easily.

Thanks in advance,

Oxy