Why am I being called at 21:49 on a saturday?!

Why am I being called at 21:49 on a Saturday?! ***- this showed up as FNB collections. How is this business practice? Its unacceptable. I will take this further as it is a complete disregard for my personal time, and seriously how is it ok to call ON A WEEKEND .I'm a private client, and i will only deal with my private banker. And judging from the results on a simple web search shows that this is constantly happening. I will be reporting this to my banker.