Contract by misleading information

I have downgraded my two lines contract to Uchooseflexi55 at the beginning of February this year, I spoke to Vodacom's agent Litha on 2 February. During the telephonic conversation I was promised that the Uchooseflexi55 will give me R55 airtime with BIS at R43 x 2 = 86 per month. However, on 1 March I noticed that BIS was only provided on one line and not on the 2nd line. Vodacom has since not responded to my request to correct the BIS on the 2nd line.