Ford Mondeo 2010 Problems

I assume the computer was replaced as diagnosed after the second episode, and that it has continued to give problems even with the new one. Intermittent problems are hard to diagnose, so you have to have some sympathy for the mechanics doing it. But given that Ford recently owned up to not looking after its customers I would approach them about fixing it, or getting a replacement car, or a refund.

If the alternator is charging ok, the problem must be a leak somewhere that causing the battery to drain. Make sure the lights in the boot and the footwells go out when you close the hatch or the doors. If they are working correctly it's really then best to see an auto electrician and have him trace the problem.
 

You can take it anywhere to have it serviced without affecting the warranty providing the servicing is done by a qualified mechanic according to Ford’s service schedule. If you do go outside the Ford service network, however, you could miss out on any updates, reworks etc that Ford might make on the run. Carmakers regularly make minor changes to fix things that crop up on their cars over time, things that don’t require a full recall, but need fixing and these are often done when the car is serviced.

Your experience is not unusual; it's quite common on European cars. Brake wear isn't normally covered by the warranty; it is lumped in with other things under the banner of 'wear and tear', which is why your claim has been rejected. However, if you apply a 'fair wear and tear' test it can hardly been said to be fair and I believe brake wear should be reconsidered and a 'fair and reasonable' wear rate should be applied to cars today.