Loss of Money in a Savings Account

I opened a 2 in 1 Savings Account by Old Mutual Finance in August 2015 and I put away R200-00 a month which leads to a R1200-00 saved to date. I was told that the R200-00 a month gets split up into a short term savings account that grows at an interest rate of 3-5% month and a long term one that grows at an interest rate of 9-12% a year. I went in to the East London branch to find out how my investment is growing and then the consultant told me that I only have roughly around R700-00. I asked the consultant how I can only have around R700-00 if I already put a R1200-00 away and the consultant told me then that the amount of money in the savings account is directly dependent on the Rand value and the lower the Rand value is the less money I have no matter how much money I put away. This information was never given to me when I opened the account. I was told that my money would grow at the above mentioned interest rate, not that I would lose money. It may not be alot of money but i was saving for a goal and I lost money, so what about other people that have the same savings account for years now and put away thousands. How much didn't they lose already.