Hi,

Recently odoo introduced the refund policy in odoo app store.

Odoo Apps Refund Policy

Claims are allowed within the first two months after the purchase date. The refund process is the following:

• The customer requests the author of the application for support using the dedicated button on his order page.
• The vendor has then 15 days starting this date to settle the claim, to fix the issue and/or to find an agreement.
• If no agreement has been reached between the two parties after 15 days, either party can request the intervention of Odoo, who will settle whether or not the customer should be refunded.

Every issue encountered by the customer in the two months after the purchase must be solved following the same process.

The customer will be refunded if one of the following criteria is met, and on the condition that he agrees not to use the application and to delete all of his copies:

• The issue concerns a bug that has not been fixed within the alloted time;
• The module is lacking a feature that is advertised on the app description page;
• The module does not install properly on the advertised version;
• The module infringes rules of the Vendor Apps Guidelines;
• The license of the module is wrong;
• The purchase is the result of a fraud or a stolen credit card.

The customer will not be refunded if one the following conditions is met:

• The claim concerns a new feature, that was not advertised in the description of the module, nor in the communication with the vendor;
• The module had a bug that the publisher was able to fix following the claim;
• The module works well, but is not satisfying the customer’s specific needs;
• The database of the customer is hosted on an Odoo online instance;
• The customer purchased the wrong version of the application for his database

Read: https://apps.odoo.com/apps/sales-conditions

Thanks

Hello, 

Here they clearly say, it is not refundable. If it does not work try contacting the author

Check this link odoo_FAQ