I have an Azure for Students subscription with web apps initially running on S1 pricing tier App Service plans, which I changed to F1 on the next day. I also created a SQL database resource. On the day I created this subscription, things were as expected and I was getting the bulk of the charge from the app services. The next day at one point as I tracked the cost breakdown at https://www.microsoftazuresponsorships.com/Usage in a JSON file I noticed that suddenly two new costs appeared out of the blue. These were the two new items that popped up in the JSON.
{"SubscriptionName":"Azure for Students","SubscriptionGuid":"{6DDC3F88-E1BD-4BB9-8DE4-CDBC340578A9}","Date":"2019-07-10T00:00:00","ResourceGuid":"{6E90401F-365E-4E92-A3C9-05BD7A5E6F90}","ServiceName":"SQL Database","ServiceType":"Single/Elastic Pool General Purpose - Storage","ServiceRegion":"US West","ServiceResource":"Data Stored","Quantity":0.055913,"Cost":0.007715994},
{"SubscriptionName":"Azure for Students","SubscriptionGuid":"{6DDC3F88-E1BD-4BB9-8DE4-CDBC340578A9}","Date":"2019-07-10T00:00:00","ResourceGuid":"{6F344F4B-7C91-4026-915A-A1B597793BE1}","ServiceName":"SQL Database","ServiceType":"Single/Elastic Pool General Purpose - SQL License","ServiceRegion":"All","ServiceResource":"vCore","Quantity":2.0,"Cost":0.199932},
As I continued tracking the costs, I noticed that these were sapping my credits away very quickly. Initially, the total was $2.54 USD and by the end of the day it already reached $5, all of it because of the SQL resources, specifically the one that has 'vCore' as the ServiceResource. I tried changing the Azure SQL database pricing tier from Standard to Basic but that did not help. What's worse is that even after I deleted the Azure SQL server/database, the cost still kept going up to $5.56 and the SQL items are still in the cost breakdown. I have no clue what's going here and how to get rid of these costs.
Remove/delete the resource group associated with these resources. When I am learning something new with Azure I create a new Resource Group and once I finished I delete the resource group to make sure no remnants are left behind that can swallow money without me noticing it.
With Azure SQL Database you have the option to choose a free tier if you create the database using PowerShell as I explained here.