You fix up your billing with Sendgrid purchased via the Microsoft Marketplace
Response from Microsoft
By design we are unable to update the Payment Instrument on Marketplace purchases, In order to update the payment instrument you would need to delete the resource and purchase the service again with the new card
I understand that the resource is now deleted and I’m currently trying to conact the Sendgrid Support team to see how you could get back the old configuration
Please click on this link to help you configure your emails
Apologies for this inconvenience, you can provide your feedback on the same via this link https://feedback.azure.com/forums/34192--general-feedback
My response back to Microsoft
How do you have "by design" a process that every time you change a credit card you have to delete the service. This is the DUMBEST thing I have heard for a long while. I wasted half my day and our programmers time having to reconfigure all our APIs that use Sendgrid after your direction to delete the Sendgrid service.
Compounding the inconvenience Sendgrid put our account on suspension because it wasn't linked to the old one and they insisted I prove that I wasn't sending spam even though for the last 2 years we sent out over 40,000 emails a month to the staff of our customers through the same service.
You can't be serious when you say this is by design. This is patent rubbish and you need to fix it, my first suggestion is getting rid of the person who thinks it is a good idea.
If you can’t do better than this, don't offer such a shoddy service.
Please advise what action is being taken to address the issue. It would be a nice gesture that your company offered this service free for a period of time as compensation for the wasted time and high levels of exasperation that I have sustained today dealing with Microsoft and Sendgrid.