ABSOLUTE BAD SERVICE AND INEFFICIENCY

I purchased a Wi-Fi device last week from Telkom Mobile in Brooklyn and was promised to heard from them re delivery etc, By MOnday following I heard nothing and went into the store again only to be told they will follow up on process. By then I told the saleslady I received sms to let me know the process was finalised so she advised she will check and 2 days later she called me to say she will delivery the device to me at work which is opposite their shop.. today 4 days later I am still waiting. I call their office nobody answers or their line is always engaged. I called yesterday after 12 times I got the guy who answered told me he will find out whats going on and revert to me and to date absolutely nothing.