charged for something i was told about when i app**** for the cintract

Ok so i took out a contract at telkom on the 14th of may for R359 and insurance for R132,the consultant told me that the 1st debit order will go through end of june,today it went through and they charged ne R1392.25,when i called to find out why they tokd me that i was charged R500 for internet services because i was data roaming but this was set up by one of their consultants and i was told that i would be charged for it,i want my money back and they should explain how their services work cause this is very misleading,please help.