Selling a service that does not exists

I received a quotation from Telkom Sales Centre for line rentals. My quotation was as follows. R206 per month for voice AND adsl line rental and no installation costs. i repeated this to confirm it. the next day i called again to place the order where i AGAIN repeated all of it and it was confirmed 'yes mam that is correct'. on monday 25.01.16 the technician arrived for the installation and i again confirmed it was for both voice and adsl which he confirmed. Friday 29.01.16 i tried to connect my axxess account to the line and it did not work. After calling Telkom i am now told i only have a voice telephone line, if i want the adsl rental as well i will need to pay an extra R299 per month rental. so Telkom have sold me a product and after i accept it and go through the whole process i find out im only getting half what i was quoted and i must pay more now to get the other half. on 30.01.16 i went to the Telkom branch to tell them to change the line to the standard R189 per month line rental and i would do the rest through someone else, they told me i will then pay the R650 installation costs. Is this usually how you catch people out!?! Sell something and THEN add on!!!!