Review Manager's behaviour

Today i went to clicks king williams town to return a kambrook blender which i bought 2 days ago, reason for my return is it doesnt satisfy me it doesn't blend smoothly and its a 500w blender, i do have a smartlife blender which is 1000w but its small that is why i bought thus jug blender and i had to return it because im not satisfied. So they called a manager which i explained all the above and she ask if the one im exchanging with also doesnt satisfy me will i exchange it i said no because its the same watts as my smartlife blender.but my complain here is how she said to me that she is giving me only today to test this new blender if i come tomorrow to return she will not take it. I was very shocked which is i never said i will return it but now i am given a condition which is not on the slip i was very disappointed by this coming from a manager