Mtn is a dishonest service provider

In the month February a sales agent from mtn called offering me 30GB of DATA at R149 a month for 24 months,when the coriouer arrived with the package it had two sim cards instead of one,each sim card had 5.81GB instead of 30GB as per our agreement.i have emailed the mtn mondo team several times trying to get assistance but the people who emailed back had no straightforward answers to my questions but money is still being deducted till this day for sim cards I'm not using and have not used because they are not working,when we checked one of the sim cards to see if its working because mtn was still deducting money an SMS came In stating that the data is almost depleted but I'm surprised how come because I have never used it.the last email I sent trying to get assistance the person said I should talk to the mtn mondo team,the very same mondo team iv been emailing but I haven't gotten any straight answers. All I want is mtn to fix their mistake because the money they are deducting is too much for me,they are taking money for two simcards and I can only afford one as per our agreement,I went to the mtn shop to find out why the sim cards were not working,they told me the sim cards were suspended.