Nelly: I'm Gonna Be A No-Show In Oz ... 'Cause I Never Agreed to Go

9:15 AM -- T-Pain will not be performing at the event either. The singer took to Twitter annoucing he "never received a payment."

Nelly's not headed to the Land Down Under anytime soon despite an Australian festival claiming he's one of its headliners.

The Boulevard tour is billing itself as "Perth’s newest and only outdoor urban music festival." It's set to go down Saturday, March 19 with Nelly, T-Pain and August Alsina all hitting the stage, but we're told fans are being misled.

According to Nelly's team ... the fest is falsely advertising Nelly's performance because he'll be miles away and has nothing to do with the fest.

His camp says Nelly loves Australia and wants to go back some day but that's not going down anytime soon and they don't want fans to hunker down for the $106 AUD ticket ... that's $75 US.

We looked, and T-Pain and August also don't appear to be promoting the shows. We reached out to the promoters at Fundamental Creative, but so far no word back.