You need to explain in detail what went wrong, I don't have first hand experience with BSD android wallet but it also works like the normal desktop wallet when it comes to wallet recovery and backup.
I understand that he had a Coinomi Wallet, but this is not the official development of the BSD team, but a third-party wallet with a huge amount of cryptocurrency supported.
Therefore, the developers of the Coinomi Wallet can help most quickly
https://t.me/coinomi_official.
I always didnt trust such wallets, especially the dekstop Coinomi was hacked in late February, the problem was in spelling of seed phrases.