No conract but still trying to ********* us to pay

We went to the Telkom store in Woodlands to request a new ADSL line, even though there was a line in the house. Almost a month later, they eventually came to install the new line. For a month after the installment, the line did not work. We have contacted them numerous times, and eventually a friend of ours, working for Telkom let us know that we had to pay a R700 deposit. That was never told to us, or did we sign for it. We then got send a bill that included a R580 installation/connection fee after we paid the R700 deposit. It was never communicated/in the contract. We still paid the monthly line rental, but the line has been disconnected several times, even though no one can provide us with the contract, where we said we are willing to pay a connection fee of R580. The layers contacted us and we sent through all the communication and info we had, but still they could not provide us with the contract, only trying to intimidate us for paying something we did not sign up for. The telkom shop and call centre is also not very helpful and can still not provide any signed contract. I'm losing money, because I need the internet to work.