Resolving an engine management warning light problem/cause

We recently took our Peugeot in for repair to North Motor Group Peugeot Workshop division (NMGPW). They had our company rep vehicle, a 308 for 13 days to resolve a problem with an engine management light indicating that there was a throttle body sensor issue as reported by Bosch Service Centre nearby. The diagnostic report from the NMGPW indicated that we needed to replace two oil pressure sensors that had to be ordered from France that would take 2 months. Obviously as a rep vehicle this was not acceptable so we managed to source these components from Durban. NMGPW were kind enough to accept us supplying the parts and they installing them. After installation they redid the diagnostics which now only intermittently generates a different engine management warning that the workshop manager personally told me is a timing advance mechanism warning that merely enhances the power of the vehicle under load or acceleration. He also said that they could not give me a time estimate to repair and that they would give a quote for the same, so I asked them to release the car for use until the above could be confirmed. I would have given NMGPW a 5 star rating if it hadn't been for the service agent that we dealt with managing our booking (name withheld intentionally). Her relay of the technical matters of the vehicle were inaccurate and confusing and I eventually insisted on speaking to the Workshop Manager on all further communications despite her attempts to relay such. She refused to release our car on collection despite us calling her 4 times to request an invoice for payment which never arrived and confirmed, not sent. When we eventually received the invoice and immediately made payment, she would not accept our bank notification of immediate clearance payment and made my staff wait excessively and with much frustration from our finance department trying to get it released. She also told my staff member who was to be driving the vehicle that we were unwilling to have the current fault repaired and "Good Luck" for not getting stuck somewhere on the road???? ***? Is she just vindictive or simply clue less? The Workshop manager assured me that the vehicle is safe to drive and the intermittent error would neither cause engine damage, restrict normal performance or incapacitate the vehicle. I also wish to extend my appreciation to NMGPW for being more than fair in their repair charges. I hope that we can get a quote and time line soon for the next minor repair so as to keep our vehicle in tip top condition. I will support them again, I just hope that we get appointed a different service agent next time. I thank all those employees that contributed.