Please follow the instructions in this TurboTax FAQ to contact customer service to request a refund: TurboTax Support.
When you enter your question, be sure to use "billing issues" as your keywords, NOT "Refund".
Alternatively, you can follow the instructions in the TurboTax FAQ below to fix your return if it is rejecting so that you can resend it.
Please post your specific Reject Code in the comments below if you need additional help.
https://ttlc.intuit.com/replies/3302275