Telkom not honouring what they Sell

I app**** for Telkom uncapped via the Telkom new business line on 24/3/2020 I was told that it will cost R699 as that is the current special ALL other cost icluded and the best was that first payment was after 3 months I received invoice over the weekend For R2103.07 to be debited on 4/5/2020 Account ***, All cost for installation connection was not for my cost I now have fibre NoT uncapped and LTE uncapped at an amount that I cannot afford and I do have a Telkom LTE contract trough Mweb that does not suffice that is why I wanted Telkom Fibre - Ive been phoning Telkom only to be told by the lady that the sales lady did not capture the info correct and that I need to speak to the originator she transfered me and the phone just rang litterly hours Please help