If you started in January 2015 and invested only R500 a month in Curro, you would have accumulated approximately 161 shares throughout the year. At the share price today, you would have made about R2153.04 profit on your R6000 investment. If the price drops tomorrow, so will your profit.
Rather stick with Sanlam. The advantage you have is that they have professionals who invest your money for you. Had you invested in Lonmin, you would have lost almost your total investment. If you invested in MTN you would have lost a lot of money. If you invested in Telkom, you would have lost money. If you invested in something else, you probably would have lost some of your capital.
I would not advise any person to take their money each month and make use of a service such as EE to invest their own money, unless they have extensive investment experience. The chances are very good that you will lose a lot of money.