LOT Airlines has displayed predatory practices towards our party. We were booked on L0138 & LO11 for March 28, 2021. At first the airline kept making changes to the itinerary, which was not a problem. Then we were told by Lot Airlines agent Paola, her agent number is #1746, :after the airline canceled our flight that we should take a voucher that can be used on future flights. My partner and I explicitly told agent #1746 that we do not need a voucher because we never use this airline. She then proceeded to tell us that the voucher could be used for other airlines within the Star Alliance Group, especially Lufthansa... which we had specifically asked her about. Under Paola's guidelines we took the voucher so that we could rebook our flight with Lufthansa. The very next day when we called back LOT and spoke to a very rude LOT agent, Sebastian, Agent #0033, who told us that we could only use the voucher for LOT airlines and nothing else. When I told him that we only took the voucher because a LOT Airlines agent told us that we can use for other airlines, he said it didn't matter. Called back LOT yesterday, June 30, 2021 and spoke to an Agent named Michael White, he failed to provide his agent number. I expressed to Michael the situation mentioned above and the fact that we were only given until December 2021 to use this voucher, keep in mind that this is an airline heavily based in Europe that is mostly under lockdown still. Michael told me that there are no refunds for vouchers and hung the phone up right in my face!! I know these kinds of calls are recorded, so I know they definitely heard their agent provide erroneous information to their customers and they aren't doing anything to recify the situation. It was extremely predatory to mislead us into getting a voucher since we throughly explained that we would not need to fly with the airline in the future due to their extremely limited destinations and reputation, as we discovered after, of being known for canceling flights last minute.