If Lufthansa says you canceled your ticket but you didn't, first ask them to send you all records showing who canceled it (timestamps, IP logs, call/chat transcripts, or the email address used), because this information is very important.
Most of the time, airlines need proof that the withdrawal request came from you before they accept it.
Next, get proof for yourself, such as your check-in records, travel alerts, emails about your credit card or booking, or screenshots that show you never went to the cancellation page.
Then, send a detailed dispute to Lufthansa customer relations that includes your booking code and flight information.
If Lufthansa still wrongly says the same thing, make a complaint about Xolvie to get it fixed.
Related Complaints
Lufthansa Canceled My Paid Return Ticket Without Consent

I had a paid round-trip ticket from the U.S. to Turkey, with travel dates from May 29 to October 11, 2024. I used the flight to Turkey without any issues, but I needed to change the date of my return flight. While trying to modify my reservation through the mobile app, I suddenly received a notifica...
Booking and Payment Problems with Lufthansa, Still Unresolved
On July 6th, I attempted to book a flight from Istanbul to New York with a layover in Frankfurt. The price was around 23,000 TL. During the payment process, I received an error message asking me to double-check my payment information. Upon verification, I found that my information was correct, but t...