Is it AirfastTickets?

Anyway, if you booked via a TA, then they'll be in charge to proceed any refunds etc. with the airline.

And unfortunately, it seems LH won't see your passed away grand mother as a (close enough) familiy member to return the money.

And yes, it's (in my eyes) a big scam that they won't return their heavily overblown YQ but only the small amount of real taxes.

Unfortunately you're probably out of luck here, unless you can prove what LH means with "close family members" - maybe as the LH lurker in the dedicated thread about it.

Oh, and one last thing: Is your ticket also non-changable?

There are some tickets which can't be cancelled, but the dates could be changed (for a fee) - have you checked the conditions? 1000€+ for a TATL flight does sound like a medium-high-economy booking class, and might not be fully restrictive..