Amazon - variable service?

This is a common situation what's basically happening is they are separate editions which are not linked together and so they are priced separately so if I list my copy of say the 1st edition at £15 and Amazon at some point start selling a newer edition at £6.99 other sellers will list the items under either of the listings and they have eCommerce software which is set to price match or beat the current lowest price even though I might have sold my copy long ago it was still the cheapest originally and so it sets a price point much higher than Amazons own (unconnected listing) if that all makes sense?

 

I did this but forgot to cancel the membership/ though they would have notified me, but took £80 without my permission, which then ran up bank charges etc. Amazon refunded me the full amount but not the bank charges.So my error cost me £16.

Amazon are a necessary evil for me at the moment. But as soon as someone else comes along who can do the same thing I will upsticks like a shot. Their time will run out, just like Tescos.