Assistant manager giggling on the phone

I purchased a pair of boots and an air mattress at the store. Sales assistant Keenan \helped\" me. I came home to find the security tags in the boot. I called the store and asked to speak to the store manager. A young female got on the phone giggling saying she is the assistant manager. I told her about the boots and she laughingly said she is sorry. She will speak to the cashiers but I must take it to the nearest store to get it off. The whole time I was on the call it sounded like she was covering the phone and there was a ****led conversation with her colleagues and giggling. Absolutely disgusting service "