How much is your monthly membership after the trial? If it is something like $19.95, you should have a better retention and there is obviously a problem with your site or your processor (I doubt this is the processor).
If your montly membership is around $39.95 - you should reconsider the pricing plans for your site. And quite frankly, in my own experience you should get rid of trials and offer an upfront $19.95 monthly membership and if your site isn't too bad - you can expect to earn $40 - $45 per member you got.
