Stereo problems

hi i have two aiwa stereo's that are both over six years old, one is the nsx-v300 and the problem with this one is that the buttons that you push don't operate the things that they should i.e the cd button often turns the radio on, the other stereo is my absolute fav as it's got a triple md player and i don't seem to be able to find anything similar on the market at all the model number is xr-hg7md the problem with this one is that it doesn't seem to want to do anything i can play a tape but i can't eject it the md player doesn't want to read any disc pre-recorded or self produced and the cd player doesn't want to work either, i am really gutted as i love this stereo and as i don't seem to be able to find a customer service number for aiwa, i was wondering if you could throw some light on the subject or suggest a company in my area (north devon) that might be able to repair my much loved stereo's