No need to worry much as everything done was digital transactions and if notice arrives you can prove it easily that it is rotation from dad's credit card to your account. Even though merchant account is used.
Still you need to hire CA and file your itr only for income from credit card cashbacks under income from other sources.
I don't think it is a right choice to show 56 lakh as business transactions and declare 6-10% as profit. As there is no sale/purchase of goods or services involved.
As per me, Giving fake, inaccurate or wrong information in ITR will take you into more trouble.