Frustratingly, the way the Avis IT system works is that once the car is scanned back in, they charge the absolute maximum possible.

It takes them around 14-28 days to work out the actual price, with/without tolls, fuel, damage etc - so I'd expect a second invoice from them in the next few weeks.

Once they send it, you can then call in and sort it (if it's not correct). Avis will tell you the paperwork is pending until such time, and will be unlikely to do very much (and they'll relay the same to BAH).

M