"Rumours that a posse of Nigerian warlocks is currently heading for the Thunderbolt Headquarters in Manchester, England, have not been confirmed."
-- Ginny Weasley, Daily Prophet (10 June 2014)
The Thunderbolt brooms are "a competitor to the Firebolt series" (Pm), but the company and designers should have ironed out the safety problems much earlier (certainly before selling version 7 to the Nigerian team), as the very public failure at the 2014 Quidditch World Cup will have not been a good advertisement!
From the Web
Screenshots of the Daily Prophet's coverage of the 2014 Quidditch World Cup: http://imgur.com/a/AXutv