Mia Xiaomi poor customer service

I bought a xiomi redmi 9T at takealot last year on the 4th of July 2021, it started giving me problems end of March this year. I sent a message to xiomi on the 1st of April 2022 informing them that my phone switched off and it doesn't want to switch on again and it doesn't even charge it's as good as dead. On the 4tg of April Matthew Hill from MIA support replied and advised me to return the device to the original place of purchase which is takealot because the device is still under warranty. I returned the device to takealot as advised. On the 19th of this month I received an email from takealot informing that the supplier says "Please be advised that the unit was retested and there is still no fault replicated." I then responded and informed them that what they saying is not true, unfortunately they insisted that the device has no fault and returned it on the 26. The phone is still not working, it's not charging and doesn't switch on at all. It's just a dummy phone. I wrote back to takealot on Friday morning the 27th to inform them that the device still not working, they replied and said they will go back to the supplier. I am still waiting for the response. I am very frustrated and extremely disappointed by the service I received. Kindly please assist