I began receiving social security at age 65, is it to late to return what I have received and change my social security retirement age to 70.? I am now 80 years old.

Hi. Yes. You are only allowed to withdraw an application for Social Security retirement benefits if you do so within 12 months of the month your benefits started (https://www.ssa.gov/benefits/retirement/planner/withdrawal.html).

Best, Jerry