Can't update UEFI BIOS

I have an Inspiron 15 7537 laptop with i7 processor and Intell HD 4400 graphic card, bought in France. It came with Windows 8.1 preinstalled on it.

For my purposes, I splitted the partition and installed Linux on the other part. Until now, I have tried: Ubuntu 14.04 (kernels 3.17, 3.18, 3.19) Ubuntu 15.10, Fedora 21, 22, 23, Windows 8.1 and Windows 10. On all these OS-es, I have the same problem: when it wakes from sleep/suspend, it needs 2-3 minutes to actually wake itself and show something on the screen. In additional, on every version of linux, there is a bug when this happens, I can't control the brightness from the function keys anymore but from the settings window it is possible as usual (until restart).

To solve this I tried a lot of suggestions, and the latest was to update the UEFI/BIOS, which is version A12 and the latest version is A13. I tried on Windows 10, Windows 8.1 (restored from recovery), and under FreeDOS (as described in the instructions here: www.dell.com/.../DriversDetails;) but it crashes everywhere right before the flashing with different errors, sometimes with error code 255, sometimes with error code -1073741819. And I don't know what to do. If I had the chance to repport this to the maintainer of the bios, I suppose that it would be resolved within days or even hours (I am a developper too and I know the process) and everyone affected with this problem will benefit from it.

I have reported this to support and all they told me was that I have to send the laptop to them and they will correct the problem. In hope that there is solution other than sending to support staff (because I want to avoid the 2 weeks delay)

Thanks in advance.