Impossible to get hold of Nimble Collection Services

Since Tuesday i have been trying to contact this company to find out which debt i have with them, but all their lines are so bad and their consultants cant even hear you. When i call their Cape Town Head office number it lets you hold for almost an hour and then refers you to the same inaudible consultants. There is no proper email to communicate with them because the one they provide when you call does not even go through. Can someone please advice as to whether this a legitimate company or not