You will have to write to the Assessing Officer regarding wrong assessment year in the specified format by post or by visiting him personally and getting an acknowledgement slip. 

To know your AO: 
login to http://www.incometaxindiaefiling.gov.in/ >> Profile settings>> my profile>> PAN details

You can write to AO in the following format: https://docs.google.com/a/cleartax.in/document/d/1jOxqQ5BcF1EUZfuAMLYHyJme48vv3oB3JwYoWa99kAY/edit?usp=sharing