Value for Money

I have an existing contact with Vodacom and it was initially for R260 a monthly. In the month of April 2018 there was an increase in VAT of 1% increasing the VAT from 14% to 15%. I received communication that my premiums will go up by plus 1% from April. Vodacom has been debuting me an amount of R308 since then. They changed my data bundles from 500mb to 629mb, my voice bundle and sms reminds the same at 200. I called the call center on the 10th of August 2018 to try and understand how did they get to 308 from 260 A month. plus 1% shouldn't be R308 but R263, and why did they increase the data only and not the whole package, the consultant who was assisting me couldn't answer, so she opened a despute query for me. The following day I received an sms that my query was solved and my data was then credited with 1gb of data. I didn't not receive a call to explain what happened and why I received that data... was it because the was an error in the data i was suppose to receive? I don't know. I checked my statement on my voda app and it shows R256 to be debited on the 15th August 2018, yesterday they debited me R308, so i am very confused with this deal that i have with Vodacom and i don't even know if the amount i am paying is correct or over inflated after the VAT increase or am I receiving what I should be receiving??????