I purchased my Macbook Pro with OS Lion from Amazon UK just under a month ago. I decided to apply for the Mountain Lion Upgrade and sent in a copy of the invoice but because it did not have the part number on the invoice they refused to upgrade.
I spoke to one of their team leaders in apple Care and I explained I was new to Apple and sure you do not want disappoint a new customer explaining I am thinking of returning my Macbook to Amazon because I am still within the months return right. He still said he could not do anything. I said will you honor the warranty and he said oh that is fine but without a part number on the invoice we can do nothing.
I spoke to Amazon UK and they said we do not put part numbers or serial numbers on our invoices but we will inform the management of your problem with the view of changing our procedures.
Amazon said they will accept a return and refund after the 30 days because I have failed to get the promised Mountain Lion upgrade.
I find it difficult to believe that Apple will lose the trust and confidence of a new customer for $20
I must admit I am tempted to return the Macbook Pro but I really enjoy the using the Apple operating system after using Windows for many years.
I realise that looking after the customer is dead and buried in the modern computer world.