Hi there!
Surprisingly they've answered and acted really quickly to get the amp from me, repair it and send it back.
They've just reinstalled the firmware and charge me £25 for it, so I was really happy on one hand but it's weird I couldn't do it myself through midi and monkey. There was no such option.
Anyway, amp is working now and is for sale for £500 (plus long-board, Midi cable) cos I've already bought Mesa single-rec and I'm very pleased with it ;)
Thanks