I'm not clear on your situation.
In case #1, you were never married, just romantic partners.
In that case, you would be required to file a return as Single, or maybe as Head of Household, depending on your other tax facts. If he filed in your name, that's fraud. You can prepare and file a return in your own name, using your own bank account. Since a return already exists in your name, you will have to file by mail. Include a form 14039-T identity theft affidavit. You can find this form in Turbotax under "other tax situations." Describe what happened and give as much information as you know about the fraudulent return. You will sign the tax return and the 14039 and mail them to the IRS, use registered mail.
https://www.irs.gov/pub/irs-pdf/f14039.pdf
In case #2, you used to be married.
If you are not legally married, but your ex filed a tax return as "married filing jointly," then what you need to do is file your own return as either "Single" or "Head of Household" (depending on your other tax situations). You will be blocked from e-filing, so mail the return and use registered mail. When the IRS gets the conflicting returns, they will investigate. You should be able to use direct deposit with your return, make sure it is your own bank account, and any refund you are due on your single return should be paid directly to you.
Your ex may be under the mistaken belief that if you were married for part of the year, he could file a married return. However, tax returns are based on your marital status as of December 31. It could be an innocent mistake, and your ex will want to file an amended return. If they do not file an amended return, and wait for the IRS to catch them, they will have to repay any improper refund amount with interest and penalties.
