I have been a customer with PrintPal for over 20 years and I have NEVER had this much of a hard time. Back in Dec 2018 I bought $81.80 worth of cartridges(4 cartridges -1 black, 1 cyan, 1 yellow, and one magenta)for my HP Office Jet Pro 8720 All In One. My intention was keep extra cartridges on hand. Last week I went to change the yellow cartridge and my printer said that the ink cartridge was inserted incorrectly and could not function. I tried re-installing it several times and still the error. I contacted PrintPal for a replacement/refund and they have ignored me to date. I have sent several emails and calls to customer service go unanswered. Thinking that it just may be a dud cartridge I purchased 1 brand new HP Yellow replacement from Staples and it worked right away!! So I know its the cartridge supplied by PrintPal. Two days later the black cartridge I have been using ran out and I inserted the black one supplied by Printpal and I get the SAME error!!! So I buy a Black one from Staples and it works no problem. So repeat this process with ALL 4 cartridges from PrintPal and NONE of them WORK !!!!! And I have gotten NO RESPONSES FROM PRINTPAL ! I am certain that PrintPal programs the chips on the cartridge NOT to function after the 180 days refund limit!!!!!! A BUNCH OF TOTAL BS. PRINTPAL, you have lost NOT only ME as a Customer but I will make sure I tell everyone in my business circles NEVER TO BUY FROM YOU !!!!!! FURIOUS !!!!