It's very common to say "多谢“ in Beijing, its meaning is "thank you very much" but you shouldn't use “book title” mark ‘《》", it's only used for the title of a book or a film or an drama, you should use a quotation mark for a word.

有“多谢”这个说法

我说：谢了啊~~,感觉南方人说【多谢】比较多

当然有

Sorry for the misleading but 谢谢 is prevalent while speaking Mandarin.