MP is working exactly as it should, and very efficiently. When it doesn't, I can guarantee the problem is not with Ebay but with the seller's lack of knowledge. So I suggest you carefully read or reread all the information Ebay has supplied on MP, so that you can fully understand what it is, how it works and how to properly use it.
Buyers can't be complaining about MP because they have no clue it's being used. They are not affected by MP in any way at all. They simply pay by PayPal, with their card, or whatever, just as they always have done. If a buyer's payment fails, that's a problem at the buyer's end, not with Ebay. You as the seller won't even know about it, as you only receive a buyer's payment in your Ebay account once it's been cleared as safe. So if you get complaints from buyers about their payments failing, as you claim, thank your lucky stars that Ebay rejected them, in order to prevent them becoming a problem for you.
I hope this helps, and wishing you all the best.
@Anonymous
