You can cancel your account anytime through the control panel, under the settings tab. First, destroy any droplets active on your account, resolve any outstanding billing and then click “Deactivate Account.”

You can destroy a droplet through the control panel, under the droplets tab. First, select the droplet you wish to destroy and click “Destroy.”
Digital Ocean - Destroy

It will ask you to confirm whether you are sure you want to delete the droplet, if you are completely sure then click “OK”

Edit:
May I ask why you want to leave Digital Ocean? In my opinion it very fairly priced and provides a great service. If you are leaving for a competitor could you explain what Digital Ocean is missing that could be added that would make the service right for you.

Kindly work on debit cards!

I have a big issue with that and PayPal is also banned in our country so we don’t have any other option!

I hope it will be fixed for us, as allot more hosting providers accept our cards but unfortunately not here :(

Thanks!