It is unlikely that the fees are refundable if the base ticket fare is non-refundable. This leaves the taxes and those might very well be what you got.

As others note, it is unfortunate, but if you cancelled before LH cancelled, then you are only due what the fare rules for your ticket provided. It sounds as though your fare rules were in a non-refundable fare bucket, although it seems worth your time to carefully review the fare rules to be certain that LH has it right.

In that situation, there is neither a valid complaint under EC 261/2004 nor US DOT rules nor is your card issuer likely to process a full refund unless LH makes a mistake and fails to respond to the card issuer (unlikely).

While unlikely, also consider exploring whether your travel insurance covers the ticket value as you are prohibited from travel (presuming that you do not meet one of the narrow exceptions). Unlikely, but worth the time to read the policy language carefully (again, don't rely on what phone agents tell you).

For the broader audience, never cancel until your flight has been cancelled or it is the day of travel. When the flight is cancelled, you are entitled to a refund. If the flight operates, then you take your lumps if you wish to travel.