There's
nothing wrong with having 7 dogs and 5 cats. As long as all the pets are taken care of and given all the love and attention they need.
The barking, on the other hand, is a problem for everyone around them (and I'm sure they're not pleased about it either). Before you call anyone, slip a note into their letter box if you can and ask them to deal with the barking problem because it's disturbing their neighbours.
If they don't, like kerriebeth said, call the police (or whom ever you need to) and have it dealt with. You shouldn't have to put up with noise like that.
Same goes if they're mistreating or neglecting their animals, call someone if they (the animals) need help.
But like I said before, there is nothing wrong with someone having 7 dogs...there are people on this site who have more than 10 and their dogs are very well looked after and loved.
Cass.