Last time I had the tank pumped (5 year intervals seems to work) I found that all the apparently independent companies all go through the same answering service and who shows up isn't who you called. The guy did a fine job but his girlfriend on the truck seemed odd. She phoned in my credit card, told me it got refused, she phoned somewhere else, said it went through. (My credit is flawless). Whatever, the problem isn't on my end.
Next morning MasterCard called me. "We want to verify with you before allowing this $2,600 charge for your Propane refill in Kazakhstan." Uh no, please refuse payment. And thanks for looking out for me.