Based on the following link (from 2013) the list of the members of the Episcopal Conference of Colombia includes Pedro Mercado Cepeda. Interestingly enough, he is listed as a priest, not a bishop.
https://www.wola.org/files/130419_cec_eng.pdf
Thanks.
On 26 July, ACI Prensa published a follow-up report on the Galat case, quoting Bishop Mercado: “[W]ith his angry response to the episcopate and his obstinate rejection of Pope Francis, Dr. José Galat has placed himself outside the communion of the Catholic Church[.] … He should not be admitted to the sacraments until he shows clear signs of repentance.” According to Bishop Mercado, “heresy and schism are typified as canonical offenses punished with (automatic) excommunication latae sententiae.” The bishop added, “Those who have committed this crime may not receive the sacraments of the Church until manifesting a visible and sincere repentance.”
Yet Church Hierarchy has no record of a "bishop" named Pedro Mercado nor Pedro Mercadao Cepeda.
And a google search for the above yields no "bishops".