Membership cancellation

For the last several months I have attempted to cancel this membership to IMDbPro through Amazon, as they are listed on my billing statement. However, each time I communicated with Amazon they claimed they had no record of any charges on my account for IMDbPro. Furthermore, I couldn't find a phone number, an email address, a chat for your customer service until just now! I have no problem strongly requesting that I be refunded for at least 5 months of billing, cuz I can prove through records of Amazon that I've attempted to cancel this membership.