Hardwired classic Ring; existing doorbell not working and battery not charging.

Please help; I am at my wits end. Every time I call ring support I get a different answer. My HARDWIRED Ring is working; however the existing doorbell doesn't work and the battery is loosing it's charge (app says it is in battery mode.) Every time I call Ring support I get a different answer and they almost always want to upsell me something. My existing doorbell is mechanical with a transformer. Everyone else in my neighborhood (fairly newer homes 2004) just followed the set-up instructions; plugged theirs in and all was well. I almost think mine may be defective and perhaps was a returned item, as their was no baggie or protective film on the unit itself and there were tiny scratches near the security screws. I found a tip on another site which told us to check to make sure the mounting plate is not screwed on too tight (as it may bow and not make a good connection) it also said to look and see if there was any residual adhesive on the contacts (making for a poor connection.) Neither of these helped me; maybe they will help you.