Citi Applications Developer interview questions

Got call via LinkedIn. Total 4 rounds of interview. 1) telephonic technical round. 1 hour 2) Skype interview, its technical round 1 hour. 3) manager round. 30 min 4) Hr round and salary discussion round 1 hour. Finally they will provided offer with current salary. At initial stage of interview, I cleared explained my current package and expected package. After , completing all the rounds they took my documents and then said that my current package was high and they can just map same salary. If that is the case why we need to join and why this was not communicated at initial process. Total waste of time.