[GST] Does GST apply on online recharges done through mobile wallets like Mobikwik, PayTM, etc.

For some reason, Mobikwik isn't sending me a tax-invoice with their GSTIN when I did a phone recharge. Its only the usual invoice with Mobikwik logo, not even a supplier address and no mention of GST anywhere.

Am I to assume that there was no GST applicable and Mobikwik isn't even registered? In that case, do I have to pay the GST out of my own pocket as RCM (Reverse Charge Mechanism), because that will be insane!

What about other wallets? Do PayTM and others provide you a tax invoice?