the alleged problem of Venezuelans who are damaging the country's economy

The number of Venezuelans leaving the country is incredibly high, these are not normal migration numbers, this is an exodus.

It is true there is a mafia at the border, but eliminating great part of it would be very easy, by getting rid of the absurd currency exchange control that was implanted in 2003 by the current government, most of the problems you mentioned regarding Colombia will cease to exist.

Venezuela has a distorted economy as a result of the absurd policies of the current government, the problem is the policies, the mafia is a consequence, not a cause.

The problem is Colombia as the first producer of coca

Yes, Colombia has a huge drug problem, but Venezuela also has a drug problem with its current government involved with drug cartels. Drug in Colombia is mostly produced by guerrillas, which are kind of an ally to the current government in Venezuela.