Misleading promises and "delay tactics" cost me a better deal

I am writing this to express my extreme disappointment with the service received from Petrie Van De Merwe at Flight Centre. After a positive experience booking a trip to Sri Lanka with him just months ago, I returned to Flight Centre to book a family holiday to Mauritius. I trusted his professional judgment, but that trust has been completely misplaced. The Situation: I explicitly informed Petrie that I had a competing quote from Pentravel that was expiring in 24 hours. Petrie assured me he could beat it. Just hours before my deadline, he claimed to have found a package 7% cheaper than the competitor, including an additional night. Based on this "good faith" assurance, I allowed my other quote to expire and even arranged extra annual leave with my employer to accommodate the extra day. The Failure: Petrie only sent the formal quote an hour after my alternative option had expired. Upon reading it, I discovered he had quoted the wrong month (May instead of April). When he finally provided the corrected quote, it was significantly more expensive than the Pentravel deal I had just let lapse. The Lack of Accountability: When I raised my concerns, Petrie’s response was that it was "my responsibility" as the customer to catch his errors. He refused to take any accountability for the fact that his misinformation led me to forfeit a better deal. Furthermore, I was told his manager was unavailable until Monday (conveniently after the new, more expensive quote was set to expire), and I was only given a generic customer service email 25 minutes before that deadline. The Result: It feels as though delay tactics and bad-faith promises were used to "corner" me into a position where I have no other choice but to pay Flight Centre’s higher price. As a loyal, returning customer, I expect Flight Centre to take accountability for this professional negligence. I am requesting that the corrected quote be reviewed and discounted to at least match the competitor’s price that I lost out on due to Petrie’s errors. Flight Centre, I look forward to your urgent response.