I am an expat Canadian working in Hefei,
Order subway 3 to 4 times per work week.
Unless you painfully have someone call them, tell them through text and a call for how you want your sub made and re verify it will be delivered wrong ...
No veggies, no cheese, no mayo or sauces requested is a common problem.
I have my assistant text, call and before delviery confirm it again, and they still send orders incorrect.
Subway from my understanding in China mainly caters to forgeiner expats .. I am lucky I have a chinese assistant that can actually do this to ensure I enjoy my sandwich the way I order it.
Nesides incorrect orders, other aspects of the service are good. Delivery time is usually prompt, drinks are well sealed and rarely are spilt, sandwich is well wrapped now and rarely come in as a soggy mess.
Lately complaint handling also has improved, sending photos of incorrect orders does prompt them to refund and or replace the order with the correct order.
I will continue to support Subway while living abroad. I just hope managment for the locations in Hefei pay more attention on training their staff to care about the product they serve!