I bought leather shoes in Sukhumvit, I think it was Tony's leather, expensive shoes, look great but he did not care about how comfortable they were to walk on. It feels like I am walking on a couple of nails, I want that they remove these and put some sole in the shoes.

I have been back to Tony's leather in Sukhumvit (next to Time Square building) a couple of times but they just do not take it serious, so will not go back there.

Do you know a good address in Bangkok?

You can try shoe repair shop at Emporium. Located on B3 level if memory serves me correct.

Appears to be the usual great after sales service to ensure that customer returns to make another purchase!