Disgraceful British Airways /comair

I bought return business class tickets from jnb to vfa. On my way back to jnb, I was downgraded to an economy seat without being mortified. When I noticed it on my ticket, no one bothered doing anything about it. The British Airways manager at Victoria Falls Airport pretended that a complaint was filed on my behalf but it was a lie. More than a month later there has been nothing from comair regarding their terrible service.

How can there be a downgrade without any communication and compensation.

I flew to vfa on 11 Dec 18 and flew back to jnb on 13 Dec 18. This is disgraceful attitude by a British Airways run operator.