Do not charge for 'free Accounts'
I just registered for a 'free Azure account' and I was charged Rs. 2 on my credit card. During registration, it asked me for my credit card details, which itself was quite uncomfortable. And then, it charged Rs. 2 without any message or prior notification. Since you anyways give away free credit, why do you need to charge on credit card? This has brought me a very negative initial impression about Microsoft and Azure. I have been using IBM cloud for several months now. Such a thing never happened there. My suggestion is, do not charge people without their consent and without reason. It is going to scar your brand image.