QSL via bureau returning

For a while now I asked myself how on earth I can get QSL returned via bureau. Most of the time I only answer bureau cards. It has been very rare I send my QSL card first. Unfortenately I dumped a lot of less interesting cards in the garbage (oh my!) So from the 3 cards at the right I could not find DF8JE. I found the QSL manager from A61BM is IZ8CLM, it is printed on the card so it is my own fault. I will send the A61BM card again. The last card is from Z60WW, their card does not have a TNX/PSE QSL sign printed on it. I guess it is my fault, I tried to return a card. However it reached me via the bureau so I presumed I could return a QSL via bureau. It did happen before but those cards are all gone in the garbage, I didn't investigate why they had been returned. I remember 2 times the operator was SK. But others could be send via a QSL system like GlobalQSL. If you receive those cards via bureau and the station is not participating the return QSL will get back to you. It is important that it is clear how to return a card, print it on your card near the PSE/TNX QSL sentence. Otherwise others presume they can return a QSL card via bureau.