Vodacom
Slow downloads

I have to lodge this complain since I bought my blackberry 9300 in the first month download speed were extraudinary an all of a suden it slow down till 1.2 kb per second and is still like that since last year 2012 June I contacted the customer call centre but there I was informed at first I should clean my browser and restart my phone of which I did but didn't improve download speed today I phoned again customer service by which they told me that I must buy data in order to download I don't understand why must I buy data what is the use of buyingg a blackberry in the first place