Loot.co.za unacceptable service and no communication

I ordered RAM from Loot.co.za in December and they promptly delivered. After realizing something was wrong, I tested the RAM and found that Memtest picked up an error with the DIMMS. I thus sent it back and asked Loot to replace the set. This was over a month ago and I have had no luck with getting working RAM in my possession. I have offered paying the difference for a different kit, and requested update, after update, with absolutely no response. Outside their call center (who cannot transfer you to any senior staff BTW), everyone just communicates on email, to which they do not respond. It feels like I am dealing with a kindergarten that employs their students as managers.