We would be happy to help you.
If reinstalling the app does not solve your problem, please contact us at https://www.handyparken.at/meta/kontakt with the following details:
1) When (date) does/did it occur?
2) Where (app, website, etc.) and
3) What (booking, top-up, etc.)
4) What specific problem occurs?
Thank you, Your HANDYPARKEN team