Very bad bad bad disgusting service ive experienced

Went to the shop to exchange shoes and the assistant at the shop was so rude telling me that i should beg them to change the shoes saying that i must stop shouting which i was not but literally wanted to me to beg which i did.. Secondly when i got to the till to pay i was told that they not taking cash and card coz it doesnt balance as they was money that was not balancing i heard them say so.. Following that when i exchanged the shoes they refused to give me a new slip of the new shoes saying that they doing me a favor by taking them.. When a customer does an exchange its called in and out and they are not obligated to give me a new slip.. The service at the store was bad ive never experienced such trauma in a store..