Thank you for contacting iTunes Store Support. My name is Agatha, your iTunes Store Support Advisor. I look forward to providing you with excellent support .
I’m sorry to hear that you didn’t receive the in-app you purchased. I understand the importance of receiving the item that you paid for. No worries, I am happy to review your account and resolve this issue for you.
In this case, Banharn, I have refunded your in-app purchased. Within 10 business days, 19.99 USD should be posted to the payment method used to make the purchase.
I would recommend that you contact the developer to know the reason why you didn't receive your in-app purchased and they are the best resource of information regarding this matter. Here's a link to their website:
lg-cs.line.me/fm/public/inquiry/index (Please copy and paste this URL on your browser)
I recommend that you avoid making any more in-app purchases from it until the developer confirms the issue is resolved.
If you want to uninstall the App, follow these steps (keep in mind that not all in-app content can be downloaded again for free, and that by uninstalling this app, you may also lose access to some of the in-app content you previously purchased):