Breach of 30 day contract

My busines have a 30 day contract with TWF Pretoria When the agents phone us, they expect us to give a quick answer about availability. We do get a lot of business from Eskom through TWF, so I believe our service is up to standard, otherwise they would not book through us Way back TWF always paid us every month end, but the last few months it's been a struggle and a fight via emails to get paid for our services TWF owes us a lot of money. I just want to warn other business against them We cannot even charge interest on late payments On average we wait 90 days for our money, if we are lucky

I really hope this complaint reach TWF