Ignoring complaints

We stay accross the street from this aclaimed 5 star hotel. Every weekend they have parties that are so loud we can't sleep. Usually we just ignore the hotel but 2 weeks ago my grandma was hospitalised and the Dr ordered rest and as little stress as possible. We thus asked the hotel after 22:00 to please keep the noise down but they ignored our request. We phoned the police but the noise remained. Last weekend the noise started and we phoned the hotel and spoke to the manager who didn't seem interested, again the noise continued. Our neighbours phoned the police but the noise got worse and the customers urinated into our garden. Today is Sunday and they have yet to stop the noise since after church this morning. We work all week and don't get any rest over weekends due to these parties on their balconies and with loud speakers and amps. Surely there must be a law protecting residents against Hotels, please can someone provide information or suggest what to do. I don't understand how this can be a 5 star hotel, is there an organisation I can contact and complain to?