card member services continual unwanted harassing phone calls Florida

despite numerous requests to stop calling me,quit this company continues to call me for sbout a year now.  Last fall I started keeping a log of dates and times I was called. So far 5 calls this month, 3 in march, 3 in february, 6 in jan., 6 in dec., 3 in nov. after I started to log on 11-15-13. I

ATT will block calls for $53.00 but I live on a very small SS check so cant do that.  I am on the do not call list and reported them just to be charged 10.00 each time and told they have too many phone numbers to block.

I'm old.  I dont know which day will be my last.  Why do they harrass prople?  How do they benefit? can anyone help me?  would changing my number help?  what can be done to stop this company?  Hello government where are you when we need you?  !!!!!  Thankfully I didnt give them info.