sales agent give wrong information

In july I enquired about fibre installation. I ordered my fibre online and a sales operator phoned me back. She advised that I can take a month to month contract for the same special as the 24 month contract. Which is R799 per month, free installation, 10 mbps uncapped internet and free line rental. Now it is done and we have the internet, but the bill came and we now owe telkom R3524, for installation, line rental etc. After inquiring about it, turns out there is no such special for month to month. only 24 month contracts. we would have made a different decision had we know about it. Now it is so difficult to get hold of them because when you phone the call centre number your are placed on hold for 15min at a time.