Mexican business mogul Carlos Slim, listed by Forbes as the richest man in the world, isn't having his best day. A lawsuit from a Colombian mobile phone company has caught up with him, and he will have to pay over $80 million in fines.

Bogota-based Empresa de Telecomunicaciones (ETB) sued Slim’s multinational company Comcel, now known as Claro, in 2006 over disagreements in the price of shared networks. Comcel argued ETB had been paying half of the agreed amount. Backed by an arbitration court, the Mexican company demanded ETB pay the difference, which came to 134 billion pesos ($10 million).

ETB, however, took its case to a Colombian court, which determined that Comcel should return the amount -- plus interest, which added up to $80 million. The Mexican company appealed the decision in 2011 to the Court of Justice of the Andean Community, which still sided with ETB.

Following the decision, Gustavo Petro, Bogota’s mayor, released a statement warning that if Claro didn't square up with ETB, he would proceed to embargo the company’s assets in Colombia. “If this does not get resolved, we take everything -- Claro’s buildings, stocks, networks. We’ll pack them up and send them out of Bogota,” he said.

Claro, which still holds more than half of the market in Colombia, said it would review the decision and appeal again.

The verdict comes at a time of crisis for Claro in Colombia. In April, social media users complained about poor service and dropped calls and started a “Turn Off Claro” campaign, which asked users to leave their phones off for two hours. Mexican media said that this was an affront to Slim and his reputation.