Don't attend the interview, they will waste your t...

Don't attend the interview, they will waste your time.
I had cleared Tesco's client round in Tesco office sent by Alten calsoft labs recruiter Amrutha and Haneef and during interview they were agreed(both Tesco & Alten) to wait one month notice period but after clearing the interview they wanted to join immediately and hence didn't release offer letter.
How ridiculous it is.. They don't behave as professional and won't pick your call and don't bother to reply over email as well after multiple follow up.