Peugeot parts are impossible to buy leaving you with a car that can't drive

My Peugeot 308 went for a service on 7 March 2019 (as always at a franchise service station). I was told that the alternator belt had to be replaced. I paid for the part to be ordered when I collected my car the very same day. I was told 1. the car is safe to drive and 2. that the part would arrive in three weeks. Two weeks later the car's engine light went on (due to the faulty alternator belt) and I had to park the car at home. It is now more than 2 months later and the alternator belt has not yet arrived. That is 1 and a half months without a car. After the local Peugeot service station was unable to get the part they contacted Peugeot South Africa (who have yet to phone me back). Every week I phone the local Peugeot and Peugeot South Africa and every week the part will arrive the next week, and every time they will phone me back (but never once have). I loved my Peugeot, but two months without a car and no support is unacceptable. How do you not have parts for your own cars?