I recently upgraded to a smartphone (finally). (I have been on Virgin PAYG for over 20 years). I switched off data roaming, but was concerned that I might be still using data. I checked my balance and I had used about £6 in three days. After giving the balance, the voice offered a choice to "find out" about Big Data. I selected the option and was told I was now on Big Data! It all seems very confusing.
If you don't have an allowance and don't want to keep paying £2, you need to disable mobile data. (Typically for Android, drag your finger down from the top of the screen. You'll see some setting options - you want to "cross out" mobile data, represented by little up and down arrows).
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