We have a stand alone shower with a ceramic tile floor and walls that was having issues with mildew or mold growing on the tile grout and caulking areas for which we hired a shower tile/grout "restoration" company about 18 months ago to fix it. This was occurring even with bi-weekly cleanings and leaving our shower door open slightly to allow for air flow.

Here are pictures: https://imgur.com/a/sdKTH9v

The restoration company asked us to stop using the shower for a week to let it dry out. After the restoration it looked great. The tile grout and caulking looked brand new. We realized shortly there after that what looked like a great cleaning job was actually the application of some kind of paint onto the grout. We didn't watch the entire job but from what we can gather they did do some kind of steam cleaning but then applied this paint product of some kind onto the grout. In a manner of weeks the paint started coming off the grout where water hit it in any way. Problem is that from about halfway up the shower walls to the top the pain is fine and actually doesn't come up with simple cleaning even with a good scrubbing. On the bottom half, mold/mildew has started to return with a vengeance and we also are now experiencing some hard water calcium build up where the shower door meets the tile. We called the company and they won't return our calls and have appeared to vanish. The big question is, how do we proceed from here to address the shower tile grout, caulk, and shower door seams?

Initial Cleaning:

1. What is the best way to go about an initial clean up? I'm assuming this is some kind of heavy duty mold/mildew cleaner, elbow grease, and complete removal of all caulked spaces. Is that right? Any tips here?
2. Any tips on the calcium build up at the shower door seams?
3. From the pictures, are there any bigger concerns like a poorly installed shower tile issue? The install was by a major home builder in Houston and we're the only people that have lived here. The shower is ~11 years old.

Fix:

1. Any tips on removing the paint product on the grout lines? Looking for what to do and what NOT to do to avoid damaging the tile. This has to be done as the top of the shower now looks much different than the bottom and we're looking to sell the house in the next year or so.
2. Once we can get the paint removed from the grout lines, is it safe to assume this is simply about reapplying the grout? Any tips there. Grout recommendations for a humid shower?

Ongoing cleaning:

1. We think we need to make a recommendation to our house cleaner on what product to use to help prevent this going forward. Any tips/advice?

Prevention:

1. We keep the shower door open about 6 inches all the time now. We can't go more than that without blocking the door into the bathroom. Any other tips?

Thanks in advance!