I've experienced a similar unhelpful attitude today.
As a registered disabled person, I carry an emergency mobile in the car. As I had not used this for some months, the number was deactivated.
I accept it was my mistake, and said as much to the customer service operator I spoke to yesterday.
She reactivated the number and told me to phone o2 after 24 hrs. to get the outstanding credit of £9.75 reinstated, with no mention of a further top up being needed.
I phoned today, only to be told I would have to top up the card by a further £10 to get the outstanding credit reinstated. I didn't want to do this, so asked if I could transfer the credit to another mobile, also in my name, but was told this was not possible.
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