You should expect your accounts to be suspended soon if you've transacted with Binance Nigeria and other exchanges or custodial service using your bank account before. I hope you will find other ways to convert your cryptocurrencies to fiat and vice versa. Are there enough merchants that you can deal with P2P?
I suggest that they could find someone that they can trust who lives outside Nigeria with a Foreign account that accepts cryptocurrency transactions and connects them with their fiat local account. I know it's hard to do but there is probably nothing wrong with trying unless the punishment is imprisonment.