Shocking customer service

I wish I could rate Opel/Delt a ' -10' stars, rating. My experiance as a Opel customer has been nothing short of absolutely shocking. I took my vehicle in 3 weeks ago as my vehicle went into 'limp' mode to protect the engin of any damage. I left my vehicle with Williams Hunt Delta / Tommy Martin Delta Roodepoort. I received a call from the service consultant explaining that the diagnostics test revealed I needed numerous parts to be replaced before they can tell me what went wrong this particular morning leading to my vehicle going into limp mode(keeping in mind I had no such warning lights). I said OK then go ahead and replace the parts needed as I am paying cash as my vehicle is out of warranty. The feedback was parts should not take longer than 3-5 working days. Needless to say 4 working days later the service consultant phoned me again to say they are struggeling to source parts and could now take up to 21 working days. So I had no option but to accept these terms as they are my service provider. However. Still no parts have been aquired, 3 weeks later my vehicle has been untouched and still with the dealer. Now I am saying, ok, since you are my service provider and cannot source the parts needed, assist me with a loan vehicle. I get feedback from the dealer, they cannot assist me as my vehicle is out of warranty. So now because my vehicle is out of warranty - then I am no longer a valued customer. Even though I have to pay cash for everything, I am not important enough as a client. I have proceeded to phone the Dealer Principal who is never availible. I have left messages twice for the DP to phone me back, which never happend. Then I proceeded to phone Opel Customer Care help line with my problem and requested assistance. I still have received no call back or feed back, yet again showing me how important a customer I am. I even told the customer care lady that I would take my issue to Hello Peter if I do net get feedback, her 'snotty' reply was that that is fine and it's my right to do so. So here I still sit without my vehicle 3 weeks later, nobody can give me any timeline as to when parts can be aquired. Dealer now willing to assist we with a loan vehicle. So much for service and customer satisfation at the centre of service providing. I cannot see why the customer must suffer when the service provider cannot assist to fix their own product's issues. This leaves the most sour of tastes in my mouth as a Opel fan. Very very very very dissapointed in the dealer and Opel.