Makate didn't respond to messages on Facebook and Twitter seeking comment. "We can confirm we have received this request," Vodacom spokesman Byron Kennedy said by e-mail on Thursday. "However, our focus is on compliance with the order of the Constitutional Court which requires us to negotiate in good faith with Mr Makate." The dispute comes a month after South Africa's highest court ruled that Vodacom must compensate Makate for the "Please Call Me" idea, which allows customers with no balance on their mobile phones to alert someone with a free text message. Vodacom's former CEO Alan Knott-Craig had been wrongly credited with the innovation, the Constitutional Court ruling showed. Makate may be entitled to as much as R10.5 billion ($672 million), with Sterling Rand due half the amount for taking on the funding risk, South Africa's Mail & Guardian newspaper reported earlier this month, citing Makate's legal counsel.