Mercadolibre.com.mx Online professional thieves - with a guarantee Mexico City, CDMX, Mexico Internet

It rains a lot here, so we must apply a waterproofing coating to our roofs to stay dry during the rainy season. We bought 30 gallons of waterproofing materials for our roof. And used 25 gallons and had 1 unopened bucket. Two days after properly applying the waterproofing materials to their exact specification - it rained, and the waterproofing material IMPERCAUCHO peeled off the roof like shredded paper. I register complaint with seller, with mercadolibre, and with impercaucho.  Mercadolibre repeated told me it was under their guarantee, then a week later said it was under impercaucho's guarantee and neither replied about refund or my losses to strip the impercaucho garbage off the roof and apply an honorable vendor's protectant (Comex).  My cash losses on the product was about $400, labor cost losses about $530, and then new materials and new labor - about ;$410 more.  Mercadolibre is nothing but liars and thieves ... they lie about refunds, they lie about guarantees, they are bold face liars.