Lay bye not an option at crossover

I did a lay-by with the store a month later went to finish of it off. But nw wasn't happy with the design anymore and wanted to change for another design same value same brand the couldn't help me. Customer services at the store was bad they even called the manage and he said his answer is no period let's not even discuss the matter. Honestly u can't change Ur mind when u have bought something there nd while I still at the store. Poor service