You might get away with it longer doing that, but the repercussions should you be caught wouldn't be lessened any by using an LLC.
The real risk you're taking when abusing a merchant account is being added to the TMF (Terminated Merchant File) and MATCH (Member Alert to Control High-Risk Merchants) lists. These are essentially blacklists for the payment card industry that all acquiring banks and processors check new applications against.
The reason the risk is not lessened is that when a merchant is added to these lists, both the company and all the company's principals' names and social security numbers are added. The list of a company's principals is something merchant account providers ask for on new account applications for this reason.
Basically, if you do something so egregious as to be added to these lists, you'll never be able to have an ownership stake in any business accepting credit cards for the rest of your life. The only way to get approved in the future would be to commit a new act of fraud to avoid the new acquirer from knowing a blacklisted person is a principal of the new company.
I don't know about you, but for any kind of entrepreneur, the prospect of a lifelong ban like that would be pretty terrifying.
