Flixbus Ticket Booking Error Not Fixed

On May 2nd at 14:10, I purchased tickets for two people for the Dortmund-Amsterdam and Amsterdam-Brussels routes for February 5th. I received the email confirmation and PNR numbers for these tickets without any issues. However, due to changes in my travel plans, I had to cancel my tickets on March 31st. After the cancellation, I was provided with gift vouchers, which I used to purchase tickets for the same dates and routes. However, I was charged an additional fee for these new tickets. Due to the rush of the day, I didn't notice the extra charge; however, today, despite checking both my emails and messages, I realized that I haven't received any information regarding the new tickets I purchased. As a result, I can't access the PNR numbers. I urgently request that this issue be addressed. The PNR numbers for the canceled trips are as follows: 3138563579 for Dortmund to Amsterdam and 3139001568 for Amsterdam to Brussels.