I got the same call they left a message and I called them back he had an Indian sounding voice very unprofessional I asked him after a bit if this was a joke and he just hung up
SCAM! They claim to be with the IRS and threaten you to get money. Just hang up and block their phone number. PS: If someone ever asks for payment with a gift card (ITunes, Money Gram, Green Dot, whatever.. it's a scam!). Legitimate companies and government agencies don't function that way.