Importing new data errors

You displayed a note that some data may have been missed, and previously when I imported data it had missed out like a big piece of time. So, I saw this as an opportunity to hopefully get all my data together. Now uploaded, I am seeing lots of duplicates but with different amounts of minutes listened of the same song in my top songs. This is really frustrating because it is clogging up space. I have reported a couple but after scrolling there is too many for me to report them all.