Vivo X200f Cannot Save Contacts to SIM, WhatsApp Not Showing Numbers

I purchased my Vivo X200f Android phone from Teknosa one week ago, and it is under warranty with the invoice. From the very first moment I started using it, I noticed that the phone does not detect my SIM card contacts, so I cannot save new contacts to the SIM. The phone automatically saves all contacts to my Google account instead. Because of this, the numbers I save do not appear on WhatsApp and I cannot use them properly.

I contacted Vivo through their website’s live support, and I also reached customer service via both their phone line and WhatsApp support, speaking with four different representatives. They asked me to send screenshots, which I did. They said they would forward the issue to their engineers and get back to me, and they collected my contact information — but I received no follow-up. A remote software update was also performed, but the issue was not resolved.

My IMEI number is: 868271079875371.
Since this problem has existed from day one and has not been resolved despite all remote support attempts, I am now requesting a full refund. I kindly ask that my issue be resolved.