Wooden Street - Different colour of wood in parts of an armchair

I bought * orchid armchair from the wooden street. In one of the chair, the part of the chair just below the seat had a colour distinctly different from the rest of the chair and also from the other chair which they tried to convince me that it was wood grain difference. After several emails and phone calls, they sent a carpenter who came and polished it. Obviously, the polish would not make any difference. Even the carpenter was mum when I asked about the difference and asked me to speak to company officials. I spoke and sent a mail too to which they responded to say it is a wood grain difference and nothing can be done about it. Leaving aside the technical part of it, aesthetically it looks bad. No one would have bought it, had it been lying in the showroom. Is this how they respond to an unsatisfied customer. The customer has no choice but to accept their reasoning. Since they have already received the money, they have nothing to lose and hence easily washed off their wants to the problem. Attaching pics as evidence