Hi @ M Gilbert ,Go to the Check Transaction in the Register. Highlight the Transaction.Click on More Actions Gear.Click on Void Transaction(s).Click Yes to Confirm.Click Save on the Transaction.Now the Balance will be increase by the amount of the Check in question.That's it.
The actions given to you by @thecreator will "restore" the amount to your Quicken account register.But you still have the uncashed paper check in hand. Take it to your local branch office and explain the situation to the branch manager so that they can redeposit the money your bank's account register.
I made my post based on the assumption that M Gilbert's account was debited immediately, when the bill pay system mailed the check. M Gilbert just confirmed the assumption and now he/she has the unenviable task of trying to get his/her money back.
If discussions with the bank prove difficult ... several of the larger TV stations in my local area offer a Helpline for consumer disputes, to help recover money. Perhaps there's one in your area, too, that you can call.