Having Problem with Subscriptions
I was subscribe Chegg study last 27 or 28 June but till now I’m not able to access of that app services while my transition is done and I have receipt from apple
iPhone X, iOS 13
To cancel the subscription please see View, change, or cancel your subscriptions - Apple Support
Strictly speaking all purchases are final (after all, you can't very well return them): please see this page for information on requesting a refund: Request a refund for an App Store or iTunes Store purchase - Apple Support
However Apple have been known to be sympathetic in cases of actual error, so it's possible that they may allow you a refund as a one-off concession: but please be aware that they are under no obligation to do so: go to iTunes Store - Contact Us - Official Apple Support . If course if the app is actually not working you have a strong case.
Alternatively go to the page suggested in the Help page linked to above: Report a Problem