Telkom over charging and misleadig

Telkom called us last month saying that we have to cancel our contract with them of 605 a month because copper is outdated and we have to install fibre we were assured telephonically that the costing would be s 100 more. And now the bill is sitting at an exuberant amount of 3000 this is day light *******. Forcing consumers to do something they did not want in the first place. I demand they refund all together or sort this problem out what they promised and what they are charging is a total lie