How to hang this shower caddy

The shower walls are BCI acrylic. We like it, no mess to clean and it went up pretty easy. This shower caddy though has been a pain in the ass. I can't get it to stay up. Contractor friend said to use heavy duty double sided tape and that worked for about 6 months. Than it gradually started to fall. Pictures of it below. I'm thinking of maybe using a screw, but I don't want to put holes in these acrylic walls.

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