1. If you bought it but didn't break the seal, ask the store to let you exchange it and reimburse you.
2. If you broke open the seal, you are stuck with the pain of your wrong decision. However, you can still use the business version. When you answer the interview questions, it will use the correct forms that you need. Sometimes people think they can use the simpler version but really can't. That kind of sounds like you, since you originally bought business version.
If you need any of these schedules… you will have to use the more capable version:
If you are sure you can use the simpler version, you could go ahead & just use the free version after you stop kicking yourself. It is 0$ to complete and send both Federal and State, so you're good. Then if something happens during the TT interview, & you find out you need something more, you already have what you need next. It won't take you very long to repeat the interview with your business version. However, you will have to pay $25 to e-file state.
In addition to the advice offered by user papa03, if you truly purchased the TurboTax Business version and not TurboTax Home and Business, then you cannot use TurboTax Business to prepare a personal return. It is only for partnerships, corporations, trusts, and estates.
If you have chosen a higher version of TurboTax Online and you wish to downgrade to a lower version, you will need to Clear and Start Over.
As long as you have not registered, submitted payment for TurboTax, or deducted the fee from your refund, then see the following TurboTax article for instructions: How do I clear and start over in TurboTax Online?