Whomever set you up did not provide justice to you and for that I am sorry. I work extensively with Clover and it will do the things you spoke of without “reinventing the wheel” and allow your business to work. Invoices and estimates can be created in an app called Invoice ASAP and the inventory should be easily trackable. Go to your inventory app, in the upper left hand corner there are three lines next to the Inventory logo, click on them, it will give you a drop down, click settings and then check both boxes, tracking and auto deducting inventory as it is sold.
Avoid like the plague!!! The system itself is passable, but lacks several of the features that our salesperson assured us would be available. The main issue is the Clover Customer Service. Trying to even access your account while speaking with a CS Rep is excruciatingly difficult! We were provided our Merchant ID number, which we enter each time we call. It never works (even though we have been told it is the correct number). So they then ask you several minutes of questions to confirm your identity. I know that is for our benefit, but shouldn't be necessary each time. We have tried to change the contact email address, ("Can't help you with that"). We tried to change the business address, ("No problem.") but it still hasn't been changed. And good luck trying to get any real technical help! Sorry to rant, but we dumped this system after four months due to the extremely poor customer service and bait and switch we feel we fell for.