Suspicious of post-air bag recall diagnosis

Hello...I have a 2004 Toyota (Corolla) Matrix and I've been beraged with air bag recall notices for the past several years. I had one airbag recall issue repaired about 4 years ago and just took my vehicle in to address a separate passenger side airbag recall. I had the work done at the nearest Toyota dealership on December 18th, 2018. They attended to the passenger side airbag. The next day an airbag light started flickering on my console (I have never seen this warning light before.) Within another day, it was on all the time. When I called the dealership earlier this week the woman I spoke with told me that she had heard of this happening before and it is often completely unrelated to the recall work I just had done. That sounded completely absurd to me, and red flags went up in my head. I took my vehicle in yesterday and they performed diagnostics. To my dismay, they told me that this drivers side airbag light and issue is totally unrelated and will cost me $485. This seems outrageous to me! I've heard they hate doing recall work at dealerships because of lost revenue. This strikes me as totally bogus and a way to ring dollars out me after recall work. Anyone have any thoughts? I now feel unsafe driving my car and I'm super frustrated. I'm attached both receipts to include all of the items that were repaired/suggested. Thanks in advance for any advice.