Buy Box Problems - Again!

Some 3 weeks ago we were organizing a sale. I set the sale prices on our site to appear after a set time. Before I could add the sale to Amazon I was called away to attend to urgent personal matters. When I got back to the office after several hours I found that Amazon had wasted no time in taking down ALL our Buy Boxes. I set up the sale prices on Amazon, but to no avail. After the sale was over I made sure that all prices on our site and on Amazon were equal. Naively I expected the Buy Boxes to return once this had been done as, going by our server logs, Amazon seemed to be spidering our site almost on an hourly basis. However nothing changed. Now after 3 weeks in the doldrums we still have no Buy Boxes, even for books that are available from no-one else on Amazon. I would add that we have been selling on Amazon for over 20 years and have absolutely no account health issues. Obviously this situation has resulted in a significant loss in revenue, both to ourselves and to Amazon - something about which Amazon seem to care little. Amazon do not want to discuss Buy Box issues via seller support. They also seem to overlook the fact that, unlike them, market place sellers do not have an army of minions readily available to undertake administrative tasks. I am hoping that someone will see this post and put a word in the right ear in order to return to whatever passes for normality. Without Buy Boxes the work now involved in maintaining a seller account is hardly worth the effort.