Bring your own food to mugg and bean

I had the worst experience at Mugg & Bean Mooirivier Mall Potchefstrooom today. I went to buy breakfast and proceeded to the counter where orders are placed. Another man came to place and order and came with his own canister of milk. The milk was then used to make his Cappucino in the same machine as all other hot beverages are made. I questioned the safety and sanitization there of and I was told he is a regular customer me therefore he brings his own milk. This is a health concern for me. What if the milk has something we could be allergic to ? What if everyone began to bring their own food for mugg and bean to prepare ?