Brikenstock Makes A Popping Sound

Last year, I bought Birkenstock sandals. After a few weeks, I went back to the store because they were making noise and showed them. They said it would go away once they adjusted to my feet. When it didn’t, I took them back again, and they were put in for inspection. A few weeks later, they came back, and they had written that there was no problem, just tighten the straps and try again. Nothing changed, and it was already the end of the summer. After all this time, the result is still the same. On the street, it sounds like I'm farting. I decided to make a hole in the sandals. I will share the results here.