Glo Kobo Glo: Touch does not work

[carmageddon]

Hi All,
I have the following issue with my Kobo Glo: wherever I touch on the screen nothing happens. I've tried the following without any success:
1-soft reset
2-hard reset
3-changed firmware
4-downloaded an image and formatted a micro SD
Every attempt did not help, every time I face the same issue: touching the screen nothing happens (almost in 99,9% of the cases).
Everything started with the upgrade to 3.15.0, therefore I tried to restore the fabric firmware with the light and power on buttons, but when the reader completed the process I was not able to select language. I, then, powered it off and on several times until I was able to select one language. At thi point I connected the reader to the pc and was able to upgrade again the firmware via Kobo desktop. After that I faced again the same issue.
To make it short: after several attempts I was able to install 3 different firmwares with the same result. I also have tried the very first firmware that was on the reader when I bought it form a colleague of mine (he kept a mini SD with the firmware) but it did not help.
Last night I left the reader with the battery plugged off, because on an italian forum I read of a person who had a similar issue and fixed it removing the battery (as you do on smartphones and pcs) but it did not help as well.
Kobo support has only said that they cannot replace the hw since I don't have the receipt (but I did not ask for a replacement!) and that the repair will cost as a new reader.
The strange thing is that sometimes everything works fine but it lasts very few time.
Any advice?