It all depends on your strategy. If you are looking for long term profits and are willing to wait then you could buy some now and see if it goes down further and buy more for a long term out look.
If you are looking for short term profits then you need to look for a buy signal, that is a new intermediate trend beginning.
The fall is mostly fears over per second billing cutting their profitability and possibilities of spending money to aquire other companies. The MTN deal fell through which gave the stock price a spurt but then they announced that they were still interested in other companies.
Currently there is not much driving the price in the near term so decide on your strategy and if you have a long term out look you could buy some of the shares now and average out as the stock price shows some strength.