I was charged after saying it’s free tria.

I'm sorry that answer may not actually address your problem. I wouldn't want to pay for a subscription on the 1st day of a free trial either.

You likely need to speak to Apple Support with regard to this. Your account is frozen because of the default of your payment method but since you didn't expect this charge, Apple Support may be able to help.

World-wide Apple Support -

Contact Apple for support and service – Apple Support

M1 Mac mini, macOS 13.5.2;  Watch, series 7 GPS/cellular, watchOS 10; iPad Pro 2nd Gen, iPadOS 17; iPhone 12 Pro, iOS 17; TV 4th Gen, tvOS 17; HomePods, audioOS 17 and Airport Express w/ Airplay 2

but as soon as I buyed it charged for the subscription and I don’t have enough amount in my bank amount for the charge to go thro.

1.

Then you need to add money to your bank card and pay for the subscription.

You can download free apps, but you may need to have a valid payment method on file, even if the app you want to download is free. 

You can have a credit card / debit card on file and an Apple Account balance.

If you have set your Apple Account balance as your default payment method, your default payment method will be used first by Apple when you need to make a payment.

Free apps has also In-app pruchase.

See -> Buy additional app features with in-app purchases and subscriptions

Buy additional app features with in-app purchases and subscriptions

See also -> Apple Media Services Terms and Conditions

Legal - Apple Media Services - Apple

2.

If an app has a subscription associated with it, see -> Delete apps on your iPhone, iPad, and iPod touch -> Delete apps on your iPhone, iPad, and iPod touch - Apple Support

• If you delete an app, it doesn’t cancel in-app subscriptions that you might have. While deleting an app, you might see a Cancel Subscriptions option. Learn how to cancel your subscriptions.

If you don't want to continue a subscription you need always to cancel that subscription in time, see the following Apple articles:

If you want to cancel a subscription from Apple

If you want to cancel a subscription from Apple - Apple Support

If the subscription that you want to cancel is not listed

If the subscription that you want to cancel is not listed – Apple Support (UK)

3. 

If you have received an invoice from Apple, on every invoice from the Apple Store and/or iTunes Store always states what you have purchased (and/or concerns a subscription) and the amount.

Tap on Report a problem on the invoice.

Or try to ->  Request a refund for apps or content that you bought from Apple.

Request a refund for apps or content you've bought from Apple – Apple Support (UK)

If you have requested a refund, you must wait until Apple has approved. Then you will receive a message from Apple.

Refunds are not guaranteed. For more information, see the Terms & Conditions.