Bad service

During the month of May I had an interview and the company that contacted me requested for me to have an Internet connection. We then got into contact with RSAWEB to install a line for us. They have been up and down to our complex since the beginning of June and came at least once a week because they could not get the line established. Eventually the technician told us the Mac address that all three of us had was different and this was on the 24th of June. In that week we contacted them to cancel because they were unable to provide the service they had promised. They responded that we could not cancel and told us that there was no manager available for them to put us into contact with. Till today we have not gotten feedback from this negligent team. The only person who has bothered to stay in contact with us is the technician. The weekend went by and on Monday the 29th of June we figured out the Internet was finally up and running after about 5 visits from their technical team. On the 2nd of July they then debited my account for R1749. 67c. Our agreement is R905. When my brother and myself emailed them to ask about the added charges no one could help us. They have never responded to emails and every time they say they will call back they never do. Now they are saying they will suspend our line. I do not understand how they operate as a business demanding customers to pay and not providing services. Never answering emails or phone calls and further yet refusing for us to cancel while they tried to sort themselves out. Through out the whole process of them trying to establish a connection they gave us a number of excuses. 1- there was a break in the line from our unit to the main fibre line 2- the initial team did not properly do their job 3- there was a problem with the otn box 4- their external service provider vumatel is having issues 5- there's a problem with your WiFi router

All we want is clarification on the account. Why are they charging us such an excessive amount without giving us the service.