>closed my SendGrid account ....continued to send me monthly invoices

I used to run IT for a medium company. The amount of times I saw this with various SaaS companies was troubling. We had hundreds of services some as small as a single manager that demanded X and company wide tools. It was frequently a several months long hassle to get them to stop billing us when we cut ties with them. I wish I kept personal records now it was a minority but definitely in the 15%'ish range.