first off, take your lunch correctly, regardless of workload or meetings, and don't let them change your time. if you know they are doing it and are condoning it, you can be termed.
our hretl was termed because the stl told him to add our lunches due to compliance during tl meetings. didn't matter that he was told to do it, the hrbp's outlook was that this is in the handbook, and EVERY SINGLE TM KNOWS BETTER. the stl and etlhr was termed, along with two tl who were changing their team's times due to compliance issues. they just wanted a great team score and didn't care that tm would go eight hours without a lunch. yes, this is my ultimate pet peeve---green scores at the expense of your team's well-being.
do not use JUST the hotline, the dtl, or the hrbp. send an email to all three. make sure you have specifics about the times that were corrected. you guys should be using MAX self service to justify punches. make sure you're putting the reason for your punches on there. if HR is keying punches without these or the written form, they are violating bp. also, keep a written journal of your punch in/out and lunch times to back it up. it doesn't matter if they just change one or one hundred--it's a serious violation, immediate termination. it also breaks several state laws (in my state anyway). some people are too scared to do the right thing. stick up for yourself and for those who can't.