Guessing the first allocation is valid for 30 days so will expire on the 15th? Do you consume from the old or new allocation at the moment?
If the data is completely free, it does not have to rollover, and there is no regulation for voice.
You can try, but I don't think you will succeed. New contracts are often sold at lower prices than previously advertised. The price increase is just unfortunate timing for you.
But please do keep us posted.
The R199 includes VAT, anyone who got the deal before April (I think) would've had a price increase.
The other amounts seem to be for other items, like contract cover, or a device (handset instalment).