Maybe a note, requesting proper sound proofing. After that I would wait for a time when they went just a little past the noise control time period and call it in. They're bound to be a little late at some time or another. Enough warnings and maybe something will be done. Until then I agree with Vertigo, go somewhere else you feel comfortable. Maybe a quiet coffee shop, a park, or a friends/ families house. In addition, maybe investing in some sound proof ear muffs.