No response from Takealot

we have been struggling with Takealot for 3 weeks now with our order. We ordered a Arktek AMD R7 240 4GB(FOUR GB) unit. Our order arrived with a 2Gb(TWO). They said we should return it and they will refund the unit. We did that and the refunded. We then ordered the 4GB(FOUR GB) unit, and they delivered EXACTLY the same 2(TWO) GB unit. I phoned their call centre and the very helpful gentleman said he would call me back to resolve. He has not phoned me yet. When I phoned again, al of a sudden their call centre is closed down. I sent amessage on their FB page, and nothing. I need this resolved as we have been waiting long enough now. Our order number is #***6