Start stop not working 2011 Dsg diesel

[Steve Smith]

Since picking up the car on Friday I noticed it is not working. When the opportunity arises when I think it should stop the symbol appears in the centre instrument display with a line through what I think is a A with a circular arrow surrounding. This is in the top right where the gear selection usually shows.
Having read the manual I believe this is due to the battery loosing power while parked on the sales pitch for almost one month. Wife has done six 20 mile journeys in the last two days almost all motorway. I was hoping that this would be enough to top up the battery but she tells me it has not done the auto cut out.

Thoughts on possible reasons?
Do you think this is a acceptable distance to top up the battery charge?
If the previous owner has disabled the system through coding how would I know of this has been coded out?

I can assure you the windscreen is not on defrost and the button to dissable it next to the gear lever has not been pressed too.

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