Eastern Railway — home interior painting

Address:

48 KABI SUKANTA SARANI, FLAT NO.-7, SHIVAM APARTMENT, 2ND FLOOR, KOLKATA-700085, Kolkata, West Bengal, 700085

I have paid rs 35650/- to national paints under asian paints for my flat repainting. It was told that entire painting will be completed within 12 days and started on and from 26.09.2019 but till date the painting has not been completed.
After receiving cheque they started blackmailng for more amount on account of stencil and texture by cash though the same was settled during colour consultation.
It is not understood why extra amount was not raised during colour consultation or during advancement of painting work.