No delivery after payment

As usual, when a Groupon call centre agent does not have an answer, all your emails get ignored!<br> <br> I purchased a Powerbank in December and was promised delivery in January. After some follow ups it turns out the item was posted, despite Groupon asking for a delivery address and not a postal address. Now nobody is able to tell me where exactly the item is. Apparently it is in Johannesburg somewhere, and the agent dealing with my query suddenly seems to have lost the ability to use her fingers in typing back a response. Lovely! Shall I just go knocking on every door in JHB then to find it?