Reliance Trends — Bill is not given

I have purchased a shoes from trends outlet from pimpalner but I have faced very strange response as I have final the shoes but just it was a single product they denied to make bill because they where telling me to add more product to buy then only the bill will be generated but as after the argument they got ready to make bill but they did not given me bill in a copy they told me that we cannot give you any bill due to single product so I don't feel this is the process it's totally wrong and making people full, please look in to this and make some effort for these behavior from trends which is well known big brand