Since credits in my account were enough for me, I canceled the subscription, then all my credits were deleted. It was unreasonable. Because all the credits were paid, you DON'T have no right to delete it. What's worse, there is no after-sale service.
If you cancel the subscription they take all of the credits you've already paid for at the end of the period. That's insane to me, those are credits I purchased. If you're taking my credits then refund my money.