No, if you were approved for more money than your insurance cost, you would not get a credit for the difference between the amount you were eligible for and the cost of the insurance.
You would have to have paid more out than the credit you received during the year for your insurance and be eligible for more credit. Meaning, the marketplace would have had to calculate your credit too low during the year causing you to pay more for your insurance than you needed to. Then you would be eligible to get a refund of the Premium Tax Credit.