For context, I have 7 Cosmos DB accounts. They are all serverless and use the MongoDB API. And all this is living under the South Africa North (with availability zone) region.
For the last 30 days, my bill for 7 Azure Cosmos DB accounts will amount to $19.47.

Additionally, in the last 30 days, the 7 accounts have incurred about 420k RU/s and 89k requests. More importantly, total data usage was 7.3MB.

According to my understanding, I should get charged about $0.335/420000RUs = $0.15 for total request units used during the last 30 days. In terms of storage, I'd assume 7.3MB wouldn't amount to 75GB of data stored but somehow my cost management analysis on Azure Cosmos DB says that it does. In essence, I'd expect a bill at the end of the month for Azure Cosmos DB that would be multiple times less than the current $19.47.

Am I missing something in my calculation of the total costs of running the database?
Thank you for your help.