Unprofessional behaviour of staff members

The store at Mall of The South closes at 7pm, but the staff closed the doors to the store early and started playing music extremely loudly and dancing while the sales assistant was still trying to assist us. The music was so loud that we couldn't hear a single word he was saying and had to request that the music be turned down. One of the female staff members had already requested that they turn the music down and seemed rather embarrassed on behalf of her colleagues, but they just ignored her request. These people need to face disciplinary action because this is highly unprofessional and unacceptable and I'll never return to this store again unless everyone is fired and replaced by new staff.