Hello and good morning everybody!

My partner and I had three (3) Miles and More e-Vouchers each. I called Miles and More to Upgrade a Swiss flight for the Two of us. The Agent ask me to provide 3 numbers from my 5 diget password. So fahr so good.
Since we are (now were) on a waiting list for a Lufthansa flight that requires two e-Vouchers each I had ask the Agent explicitly to deduckt one (1) E-Voucher for the upgrade from each (my M&M account and my partners M&M account. It took less than a minute and the upgraďe was confirmed. Good. Then I ask the agent if she does not need my partnes FFL number and 3 numbers from his 5 diget password. She replyed "...I have the FFL numbers on file of the booking..." At this point I thougt Everything okay.
Yesterday I checked my upcoming bookings. And WOW! Two e-Vouchers were dedicated from my account, and waiting list upgrade for an upcomming LH flight was canceled. Unbelivable how this "LADY" lied to me.
How can I get Miles and More to correct this? For quality reasons they record conversations anyway.