Their rates changed a few months ago. They mailed letters about it and there was a big uproar about it here.
https://www.zombaio.com/rates.asp
You're being charged 14% because you have a high chargeback rate. Your base rate of 9% + 5% for the high chargeback rate.
https://secure.zombaio.com/zoa/tool_...yout_rates.asp
"Zombaio's low transaction rates requires you to have control over your chargebacks. The chargeback ratio is the number of charge backs issued in a period of four weeks divided by the total number of transactions in that same period. If this ratio is 1.5% or more, a surcharge of 5% will apply to the base rate for that period. Once the ratio is below 1.5% your rate will be restored to the base rate. The average chargeback ratio is at 0.65% for an high risk merchant."