Less than a week after Apple Pay went live, two of the country's largest drugstore chains have stopped accepting payments made through the system.

Drug retailer Rite Aid blocked the service, and on Saturday CVS Health followed suit at its pharmacy stores. The retailers, however, weren't in the list of those specifically named as supporting Apple Pay when the Cupertino-based company revealed the payments system last month.

In fact, both retailers have shut down the NFC payment terminals that were installed in their stores, blocking not only Apple Pay, but also Google Wallet as well as other contactless cards. The move stems from the fact that the companies are part of a consortium of retailers called the Merchant Customer Exchange (MCX) that is already working on its own mobile payment system aimed at enabling the merchants to avoid paying transaction fees to credit card companies.

Slashgear published a leaked internal memo last week in which Rite Aid confirmed that it's focusing on a rival mobile wallet. "Please note that we do not accept Apple Pay at this time. However we are currently working with a group of large retailers to develop a mobile wallet that allows for mobile payments attached to credit cards and bank accounts directly from a smart phone".

Dubbed CurrentC, MCX's new mobile payment network isn't based on NFC, but instead relies on QR codes that both customers as well as sales associates scan to confirm a transaction. The system is expected to become available in the first half of 2015.

Aside from Rite Aid and CVS, other members of the consortium include major retailers like Wal-Mart Stores, Best Buy, Target, and many others.