Foundever Chat and Non Voice Process interview questions

I had a very bad interview experience at foundever, where I went for a walk in drive for non voice chat process and was selected for second round that is assesment and I got a score of 80% in assesment and they told the that the third round will be virtual and was asked to contact the hr. I contacted them multiple times, I got no response from the hr and suddenly they are telling me that I didn't get selected for the third round. Communication part from the hr is not clear and they shouldn't say I got selected for third round then change their statement and say didn't got selected. This was the worst interview experience I had.