I do not know the reasons to why they call but since I got my new phone they have been calling me around 4x a week and it's very creepy and I do not like it and I don't want to get charged when I answer so there is no solution please help me

You're answering is the reason they're calling. Make sure you're not in any way so they draw blanks from your number. Try blocking the number if you're able to, look for a blocking app on a cell, or maybe a call blocker for a landline. If you don't wish to spend any money, not answering is free.