Bata India — Wrong shoes

Please note yesterday I went to the Bata showroom at Viviana Mall and bought one pair of slippers for 600/- and one pair of rainy shoes for 500/-. The shoes were tied together, so I tried one and purchased it, and the slipper I word it from the show room itself. When I reached home to give it to my sister, I noticed one shoe was size 3 and the other was size 4. The same was not checked at the counter, and why are wrong sizes tied together. Moreover the sales girl was not bothered to help in finding what I wanted, she was busy on the mobile. Service at Vivian mall Bata showroom is pathetic. Please look into the matter. I have faced this problem before also with the sales person and the counter person also is not helpful at all.