I purchased about a dozen ink cartridges for my HP Photosmart 7520 printer. I do a high volume of business and personal printing so the price of the OEM HP ink cartridges was getting to be too much. I decided to try the Inkjet Superstore because not only were their advertised prices low, but they claimed to have cartridges with a "New Chip" installed indicating that my HP printer would operate as if the original OEM cartridge was installed. WRONG! I initially installed the black XL cartridge and the minute that I closed the lid the printer displayed the message "Non-HP cartridge Installed" and locked the printer up. I tried many times to manually reset this and even removed the cartridge and put the original HP OEM cartridge back in. Nothing worked. The printer was a brick and nothing made it respond. After several phone calls back to the HP tech department and about a dozen emails back and forth, I was finally given the secret code to forcing a reset onto the printer. This worked just fine. The problem is that HP printers send out usage information and my installation of the Inkjet Superstore cartridge immediately voided out my factory warranty. I have an advanced degree in computer science from MIT. I called the customer service department of the Inkjet Superstore and spoke with Chris. He treated me like I was a complete idiot that didn't even know how to turn on a printer. I calmly explained that I had an advanced degree in computer science and to simply tell me what I could do to make the cartridges that I had bought work with my printer -- after all, the warranty was voided now anyway so I had nothing to lose. He gave me a list of generic YouTube video links that showed me how to install an ink cartridge in my printer. Duh. Again, I called back and got Chris. After several phone calls with Chris, he finally gave me an RMA to return my ink cartridges. I packed them all up in a large bubble wrap envelope and he received them on the 7th of June. It is now the 23rd of June and I have still not received one red cent. I have called and emailed the Inkjet Superstore a number of times the past couple days. Of course I get Chris each time -- he must be their only customer support person. He tells me -- now get this -- that they only received 3 ink cartridges back from me and they were all empty!!! However, as an accommodation, they were going to refund me for 2 of the cartridges. How sweet of them huh? Incredibly, after I tell them that I am going to spread the word far and wide across the internet about their *** ink cartridges and lousy customer service, they send me a photo that they took TODAY with two ink cartridges in it that had been opened telling me that this was somehow what I sent them almost a month ago. Duh. Oh yeah, the emails purported to come from someone named "Kyung S. Chung" but the email address was "chris@***.com." Folks, spread the word far and wide that this outfit will sell you junk cartridges that virtually destroy your printer, give you lousy customer service and then screw you out of giving your money back. DO NOT BUY FROM THE INKJET SUPERSTORE!!!