Tatinha,
In your sentence, I'm not sure what the word 'partner' refers to specifically. 'Partner' often means 'boyfriend/girlfriend' or 'spouse', but sometimes it can mean 'business parter'. Neal is right about the meaning of to be 'taken for a ride'.
It sounds as though the writer was trying to say, "Your business partner took advantage of you and/or stole money from your business because you were not well organized financially." To prevent him/her from stealing from the business.