South Africa; this was unheard of before black rule:

Something like that happened to my parents-in-law about 20 years ago; they were just into retirement in a nice area of southeast London when slowly but surely their neighbourhood was taken over by west indians. Soon afterwards they couldn’t put up with al fresco steel band and rap parties in gardens lit up with bonfires which lasted over the entire weekend period, they had to sell up their home and move away.