I also have the same issue with MasterCard, but Visa is working fine.
Frustrating at times, but QR IT is hopless in some cases. It is truly frustrating when these typical QR malfunctions arise, but follow Havoc10G's advice and give up trying to help QR improve. You will for sure waste your time and bring more frustration upon yourself. They do for sure miss out on some buisiness this way, but they probably dont care.