BT Group Software Engineer Java Developer interview questions

first round was very easy and polite then next day was my joining date with other org .but the hr from the bt group told one managerial round you tell them we will release offer within 2 days but i didn't trusted her and postponed joining date next round suprisingly system design round and interviewer was a mad person what ever he fixed in his mind that we have to answer ,no patience, not allowing to complete what we say. interview seems ok .suddenly got rejection mail. thank god i postponed the date as i left early existing job due to her i would have been jobless. "NEVER EVER TRUST ANY HR AT ANY COST"