Getting sick and tired of having my business disrupted by Amazon

In the last week I have had my business on amazon light up with performance notifications due to two orders. One order a customer left a negative feedback regarding the packaging, (when every other customer has no issue) and the other issue I have faced is a customer blatantly scamming me and winning the A-Z case even though they returned a different item (serials do not match) So I am not only the cost of the item down, amazon has awarded the scammer and my account is now in ruins. I have been begging for help from @Sarah_Amznand @Simon_Amazon for about a month now and they have also stopped responding but are responding to others. I wouldn't come to the forums for help if seller support were actually of some use. It's so frustrating when you have a non issue causing so much havok on your account and you can't just speak to a person with common sense and can see what is going on. The beginning of this year we had all our funds frozen causing massive problems across the uk because amazon needed uk sellers to somehow re-verify they are from the uk even though they have all our details on file already! Once that issue was sorted I'm now again fighting for my account due to scammers and people who like to complain for the sake of complaining with no intention of returning a product if they are unhappy. Everyday it's a sellers word against dishonest buyers trying to get free things even with proof amazon does nothing. Why is the support for sellers so non existent? With ebay you can ring up explain your problem and 9/10 you will get someone friendly who can actually point you in the right direction or help. It's insane what sellers have to go through on here