Billed for 2 bins since 2012

I have been billed for 2 dustbins since 2012 despite several separate service tickets being logged and follow ups to explain that I only have 1. Every communication with them results in another form needing to be completed by another person in another department. No one takes ownership and no one actually helps me. I strongly doubt I will ever get much of the roughly R7680 the owe me for overbilling or if I will ever actually only be billed for 1 bin.