What type of GetEntitlements Response is received when a customer cancels his or her subscription before the expiry of the contract.

There are two SNS topics available for use when it comes to SaaS products on AWS marketplace:

1. aws-mp-entitlement-notification: This topic notifies you when buyers create a new contract, upgrade it, renew it, or it expires.
2. aws-mp-subscription-notification: This topic notifies you when a buyer subscribes to or unsubscribes (cancels a subscription) from a product.

For your use-case scenario, you need to subscribe to the SNS topic "aws-mp-subscription-notification".

When a user does unsubscribe from a product, a notification will be published to the SNS topic and delivered to its subscription. The message structure will be as follows:

{
    "action": "<action-name>",
    "customer-identifier": " X01EXAMPLEX",
    "product-code": "n0123EXAMPLEXXXXXXXXXXXX",
    "offer-identifier": "offer-abcexample123",
    "isFreeTrialTermPresent":"true"
}

The JSON attribute "action" in the above message will contain the information you need. If a user unsubscribes, the "action" attribute will have the following values in two different notifications:

1. "unsubscribe-pending": This action type message is sent first when a user unsubscribes. This indicates that the seller has a limited time to get final metering records sent before the buyer is cancelled completely.
2. "unsubscribe-success": The unsubscribe-success message signals the completion of cancellation.

Therefore, as soon as you receive a "unsubscribe-pending" message over the SNS topic "aws-mp-subscription-notification", it is an indication of user unsubscribing from the product.

You do not have to call the GetEntitlement API call explicitly to get that information.