iRobot Roomba i4 Vacuum Cleaning Robot

We have one refurbished iRobot (that does not self empty) that came from a different seller whose name begins with a W& ends in a T. It is fabulous. This review is NOT for that vacuum or their company.This self emptying one, however, arrived malfunctioning out of the box with a clicking noise from iRobotIt then spun around wildly, BANGED into the furniture and walls, did not clean well, died in the floor, said it was stuck when it wasn’t, and needed to be rebooted… EVERY TIME WE USED ITiRobot was NO help and immediately informed the Amazon agent that Amazon was responsible for refunding the $ for this item when Amazon and I called them on a conference callAmazon was additionally NO HELP, gave me conflicting instructions, and so far has not honored their A-Z guarantee (after over a week of begging iRobot for a prepaid return label with Amazon reps in writing, Amazon told me to not contact iRobot without them on the phone, to file an a-z claim, to throw the vacuum out, and that they would handle this difficult seller bc that is why they had this a-z policy, but is now (a week later) telling me to instead return an item they told me to dispose of).SO FAR this has been NOTHING besides a VERY expensive hassleI have spent hours on the phone with agents at Amazon who say how sorry they are, but cannot actually helpI have uploaded videos and screenshots that came directly from the malfunctioning robot vacuum for evidence. When we used it, we followed all troubleshooting, cleaning, replacing parts, and rebooting steps daily to try (in vain) to get this broken piece of garbage to workCAVEAT EMPTOR when purchasing anything from a 3rd party seller on Amazon OR from iRobotAmazon will more likely than not back up their seller if it is a big name instead of their customer (even if their customer has been a prime member for longer than iRobot has even been a company)iRobot will not send you a prepaid label and will ask you to pay out of pocket to mail their broken garbage back to them