I changed my iTunes Plus plan from monthly to yearly, but my Dropbox account is now Basic.

Initially, I had a Dropbox monthly payment plan, but I canceled it in January and switched to the annual Dropbox Plus plan. I have a receipt confirming the successful payment. However, I recently noticed that the app is unable to charge my card and is prompting me to update my billing address. I reached out to Apple Support, and they confirmed that my monthly plan was canceled and that I purchased the annual plan. Despite this, my attempts to speak with a live representative at Dropbox have been unsuccessful. Moreover, my account now appears to be on the Dropbox Basic plan instead of the annual plan I paid for. Last night, I finally managed to chat with a representative who advised me to refresh my purchases, but I encountered an error when doing so. The agent informed me that she did not have the tools necessary to resolve the issue. Given that my account has been downgraded and customer service options for Dropbox Basic are limited, how can I get the appropriate assistance to rectify this problem?