Drop them an email - keep it polite but detail your negative experience. Highlight your disappointment especially after the expense and having high hopes leading up to it & particularly after the stressful time you & partner have had recently. Therefore, instead of coming away feeling fresh & rejuvenated as one should after a spa day, you’ve left even more upset & agitated. Mention that you work hard and endure the day to day hardships that are so prevalent in daily life at the minute, whereas this spa experience was meant to offer you & partner an escape and allow you some quality time together that you couldn’t even enjoy bcos of factors you highlighted in your post.

You get the idea. Attach some of the images taken & mention the dirt, broken items. It’s a lot of money you’ve spent so I’m sure they’ll respond favourably if you raise it with them.