Xiaomi India — Invalid invoice provided by mobile shopkeeper

Address:

Patna, Bihar, 800006

Sir I have purchased a mobile phone 'REDMI 3S+' from a shop in mussalahpurhat, patna in bihar state on 08th Nov 2016.
Sir my mobile accessory got damaged on 25th Feb 2017. When I went to its service center and shown the invoice, he told me that this invoice doesn't have VAT/TIN no. and then i went to the shopkeeper and asked him to provide me the valid invoice but he totally refused to provide me the same.
Sir this is my humble request to you kindly help me to come out of this problem and force him to provide me the authentic invoice.