Correct. This was not permitted to be deposited into an BDA IRA. By making the deposit, the IRA to which it was deposited fails to be a BDA account, despite how the account is titled. The account instead constitutes an IRA owned by you. The amount deposited is an excess IRA contribution to the extent that the amount deposited exceeds what you were eligible to contribute to your traditional IRA as a new contribution for 2018. The amount that is an excess contribution is subject to a 6% excess contribution penalty each year that the excess remains in your traditional IRA. You'll need to contact the IRA custodian to get this all sorted. You can avoid the 6% excess contribution penalty for 2018 by obtaining a return of contribution before the due date of your 2018 tax return.
This unfortunate error happens often enough that Congress has considered changing the tax code to allow these rollovers by non-spouse beneficiaries, but none of the bills containing this provision have progressed very far.
