B8 ad Blue fault

[AndyLINCS]

Hello - looking for a bit of advise from you knowledgeable people
I have a B8 4 motion estate, got the ad blue top up screen up so added about 7lts in it, job sorted I thought display cleared all good.
Hour or so later got screen display - ERROR AdBlue (DEF)no start 600mi
So booked into main dealer still under extended warranty and after having for a week and saying that they needed factory information, rang yesterday say its done - happy boy !
Better half picked up today, she couldn't get hold of me, paid 300 quid out -very pee'd of on her return (not her doing)
They have said carry out diagnostic into ad blue warning on - found over full 150% - corrected level - carried out SCR event re set and road test = ok
labour - and 10ltr of ad blue.
Am I missing something folks ?? - tank overfull 150% - surely I would have Ad blue soaked feet FFs if that's the case and they have charged me for 10Ltrs of Ad blue - It looks like we have our leg lifted here
Could I beg advise please before I venture in for a discussion about the robbery that's just happened to Us
Thanks Andy