Airtel — unnecessary charges for activation of 4g sim

I wanted to port my docomo sim card (Which is undertaken by airtel now) to jio but as soon as i sent the port message, i started getting calls from airtel's feedback service for an entire week, forcing me to not change to jio and try airtel for months. The executive clearly told me that there will be no charges for upgrading my sim card from docomo to airtel 4g and no id proofs too. But today as i sent to the showroom, they're asking for ₹300 charges and id proof. So they won't even let me port to jio but also can't even live up to their promise.