Get full refund for a defective product

Hello,

I would like to know how to go about obtaining a full refund for Adobe Send & Track. I signed up 2 months ago but whenever I have used the service, only some of my recipients received their documents. I have posted to the forum for help but have received none.

I believe the "Cancel" option will only give me a partial reimbursement.

Thank you in advance for your help,

Daniel