To contact TurboTax, see: What is the TurboTax phone number?
Be careful with any solicitation claiming there is an issue. If your returns are accepted and approved without issue, then any further contact with the IRS should be verified.
The only way there would be an issue would be if the stimulus payments were received, but also reported as missing on the Recovery Rebate Credit.
For more information, see: Avoid scams: Know the facts on how the IRS contacts taxpayers
Economic Impact Payment Information Center — Topic D: Receiving My Payment | Internal Revenue Servic...
Recovery Rebate Credit — Topic E: Receiving the Credit | Internal Revenue Service
