UOB Money Changer Changi Airport T1,K27

I keep the SIM cards I purchased online from Sprint.
Service was the worst I've ever had.
Nothing to explain. Thank you, but no. Nothing. Give the card, and the woman walked away. Even standing there, I had to wait five more minutes to beg for a SIM card extractor. 

The female Indian employee was incredibly unhelpful when we asked questions. we arrived at the counter, she was talking on the phone, but it seemed like she would prefer to finish the call than end the interaction with the customer. "Anything else? bye" was her final response before she picked up the phone.