Instruct: Classify Amazon reviews into positive or negative sentiment
Query: HP 88 black/yellow

Very, very disappointed with the return/exchange policy concerning office products purchased. I purchased my HP 88 black/yellow officejet printhead for my Brand New HP Officejet Pro L555 all-in-one printer due to it's warning of the black out of ink light.I ordered on March 1, 2010, and received it within a reasonable time to Hawaii. So, I had no choice but to continue using the original ink printhead to keep printing until then. However, to my surprise the original ink printhead kept printing. Therefore, I delayed to the install the new printhead until June. Only then did I discover that the new printhead does not work or register at all?!I wanted to exchange it for a replacement, but was told it was not possible?! Too late to return or exchange. Very dissatisfied!!!Order at your own risk if HP products are actually working merchandise?!