You are replacing far more frequently than necessary.

Even a semi-serious racer type who tend to stress the equipment will not be changing the chains that often. A skinny hyper-glide chain used on 10speed cogs (dura ace, ultegra) will need replacement maybe every 2000-3000 mile.

If you don't ride through mud, through sand on the beach, your chain should last you more than 3000 miles. A recreational rider could probably get away for 4000 miles or more.

No need to replace the chain ring!

brake pad should be replaced when they are worn or after two years or so. time limit is because the rubber compund on the pads gets physically old but I've regularly kept them for like 4 years at a time with many many more thousands of miles.

Your 2000-3000 miles per year is still considered recreational, so go to some other bike shop for a tune up. Have them check the "stretch" of the chain. It's probably fine. If it is fine, no need to replace the clusters or the chain ring.

sheesh!! taking advantage of you!
Smilingcat