Sorry to hear this. Check the LH forum here for threads on baggage at FRA. It sounds like they are horribly backed up and taking days to route bags. Someone just posted that they got their bag in Europe after 3 days.

QR has agents in the USA so try pursuing your claim for reimbursement with them when you get home (even better if have a travel agent who can intervene with them). UA baggage in the USA may also be able to help you with both tracing the bags and getting reimbursed.