No response - bad service to loyal customer

I have been a Takealot customer for many many years. I buy from them very regularly and have actually not really experienced any bad service. Until now. A few glitches happened with a previous order, but it was handled and fine. But the most latest issue is the one that has brought me to HelloPeter. I bought a powerbank in December 2016 as a Christmas gift. Just over one year later (and a week or two out of the guarantee period) it just stopped working. I have contacted Takealot various times and just receive no response or feedback at all. What I would expect is a replacement on this item, but in the very least, a response to my various queries about how I would go about getting this fixed now? I understand it could be a supplier issue, but if so, put me in contact with them. Do something. But ignoring me is not good customer service at all.