2004 Toyota Corolla - strange engine noise after tune-up

I recently took my 2004 Toyota Corolla in for a 60,000 mile check-up. They changed the serpentine belt replaced some air filters, did an oil change, etc. After I got my car back, I started noticing a concerning noise when I started my car and when I idled every time I stopped until I had gone over 25 mph or so. So, while sitting in a parking spot and in the neighborhood at stop signs. The noise was basically the same as regular engine noise, but 2 or 3 times as loud as normal. I took it back to the shop and told them all of this and left it for a weekend while I was going to be gone (it won’t make the noise after the engine is warm and you restart the car). When I returned, they told me it was normal engine noise, that they checked the new belt and everything they had touched and nothing was wrong. They then guilted me saying they could try replacing the belt again to see if it went away, because they want me to be happy, but that they couldn’t find anything wrong. What should I do? Force them to put in new items when they think the old ones are fine? Go to another garage and potentially pay more? Please help!