Quick on sales but almost no aftersales support.... Would not recommend

I have been getting fair service from Webafrica for the past year or so now. In Jul 17 2019 I officially requested that my service be downgraded from 20Meg Fibre with 600G cap costing R1239.00, to a 10Meg Uncapped Fibre Costing R620.00per month as advertised on there site. I phoned there sales and was answered within seconds and they also confirmed it. So I put in my ticket for downgrade and gave the calendar month bonus. Instead of getting a R620.00 per month bill since then I have been getting a R1365.58 bill a month now since the downgrade. I have been trying with no success to get the billing department to respond to my requests via phone calls, emails, tickets, Whatsapp and Facebook with no success, hence I have cancelled my services now and stopped paying. Up to now since beginning Oct 2019 i have had no reply from the billing department at ALL, and holding 10-30 minutes at a time on the phone until it disconnects from there side with no answer. I WOULD NOT RECOMMEND WEBAFRICA to one of my clients again and are busy moving 15 of my own customers that I have referred to them in the past to another ISP