FAULTY DEVICE - WARRANTY EXPIRED DURING LEVEL 5 LOCKDOWN

My mother-in law, aged 73, renewed her contract with MTN, got a Samsung Smartphone. The device started to give her problems just before the Lockdown started. She took the phone to SAMSUNG , as it was still under the 6-month waranty, they then told her, that they can not take the device to get it sorted, due to the lockdown. After the stores were allowed to reopen, she took the device to Samsung again, as the phone got hot and the battery did not last at all. They then told her that unfortunately her warranty expired and she needs to pay for the repairs as the motherboard of the device needs to replaced. How can it be my mother-in law's fault that her warranty expired when the WHOLE country was under lockdown???? I want to know that... She took the device to MTN, with a lot of problems, her device has been sent in for repairs, for such a long period she had to battle without a phone. Which I feel is not fair. She did not break the phone, they told her that the device had a factory fault, the faulty motherboard. We will see now when the device is fixed, if there will be any costs involved. But I feel that they should have just replaced the device. I will post this on SAMSUNG too.