Urgent hell needed

I am battling to lodge a complaint to one of the employees of absa bank and she is an infrastructure manager in mooi str jhb. It's kind of a person issue but she going on Facebook and bad mouthing me an my company and it's becoming serious now as she calling my clients and I'm loosing business. Is there anyway this can be solved as I'm desperate as I'm sure absa has code of conduct rules for the employees not to do this and she in the banking sector. Please help . I went to her branch and gave evidence to her so called manager but I guess she was fronting as nothing happened