Pathetic Service - no response

Trying to get an answer from billing dept is impossible. Non Profit Org I work for has a credit due for a cancelled service (telephone line cancelled) but nobody in billing responds. Tried submitting query via website form, tried phoning, tried e-mailing but just dead silence. Anybody by any chance have some way of contacting a human at Telkom please? We really need to get this money due to us back from Telkom.