Marketpress payment gateway not working

Hi Guys I hope you are doing great!

I am a bit desperate here, hope someone can help me...

I've hired 3 developers now and no one has been able to figure out how to add a new payment gateway for Marketpress (i guess they are not as good as they said) the thing is that trying to integrate a payment gateway with a processor named Conekta (in Mexico) there is an error that no one can figure out why is happening, the error I get is:

Fatal error: Uncaught exception 'Conekta_ParameterValidationError' with message 'The minumum purchase is 15 pesos. Check that the amount is in cents as explained in the documentation.' in /home/barknla/public_html/wp-content/plugins/conekta/Conekta/Error.php:38 Stack trace: #0 /home/barknla/public_html/wp-content/plugins/conekta/Conekta/Requestor.php(85): Conekta_Error::errorHandler('{"object":"erro...', 422) #1 /home/barknla/public_html/wp-content/plugins/conekta/Conekta/Resource.php(64): Conekta_Requestor->request('post', '/charges', Array) #2 /home/barknla/public_html/wp-content/plugins/conekta/Conekta/Charge.php(23): Conekta_Resource::_scpCreate('Conekta_Charge', Array) #3 /home/barknla/public_html/wp-content/plugins/conekta/index.php(231): Conekta_Charge::create(Array) #4 [internal function]: MP_Conekta->process_payment(Object(MP_Cart), Array, Array) #5 /home/barknla/public_html/wp-includes/plugin.php(525): call_user_func_array(Array, Array) #6 /home/barknla/public_html/wp-content/plugins/marketpress/includes/public/ in /home/barknla/public_html/wp-content/plugins/conekta/Conekta/Error.php on line 38

Can any one please be so kind and take a look into it and guide me through?

I really appreciate