Here is a story that might help you deal with lack of gratitude for apologies when people push you too far.

At my old workplace, the Accountant Manager always fiddled the figures so they didn’t have to pay us commission. One week, I wandered in to the office for some issue and one of the accounts girls asked “Salvo, you always have a smile, why are you always so happy?”. I replied “whenever something bothers me, I just ignore it and bottle up the anger until it boils over and I go Postal.”

She laughed, the Accountants Manager’s face went white and we got commission paid the next month.